Lectures given at conferences
  1. Der Satz von Mordell-Weil via Methoden der Nonstandard Analysis.
    [The Theorem of Mordell-Weil via methods of nonstandard analysis]
    Modelltheorie (Anwendung der Modelltheorie auf die Zahlentheorie), Oberwolfach, 9-15 January 1977.
    {Tagungsbericht Oberwolfach 2/1977, p. 4}.
  2. The Theorem of Mordell-Weil via Nonstandard Methods.
    Algebraische Zahlentheorie (H. Hasse, P. Roquette), Oberwolfach, 14-20 August 1977.
    {Tagungsbericht Oberwolfach 33/1977, p. 16}.
  3. Nonstandard Diophantine Geometry.
    Recent Developments in Number Theory (P. Ribenboim), Queen's University, Kingston, Ontario; 2-20 July 1979.
    {Queen's Papers in Pure & Applied Math. 54 (1980), pp. 129-172}.
  4. Über rationale Punkte auf Kurven von Geschlecht $g \ge 2$ (Satz von Mumford).
    [On rational points on curves of genus $g \ge 2$ (Theorem of Mumford)]
    Algebraische Zahlentheorie (H. Hasse, P. Roquette), Oberwolfach, 12-18 August 1979.
    {Tagungsbericht Oberwolfach 34/1979, pp. 7-8}.
  5. Nonstandard Methods in Diophantine Geometry.
    Journées Arithmétiques 1980 (R. Odoni), Exeter, England, 13-19 April 1980.
    {London Math. Society Lecture Notes No. 56 (1982), pp. 417-449}.
  6. Die Mumfordsche Theorie der Thetafunktionen.
    [Mumford's theory of theta functions]
    AG Geyer-Harder: Die Vermutungen von Hodge und Tate (R.P. Langlands, M. Rapoport), Oberwolfach, 12-18 April 1981.
    {Tagungsbericht Oberwolfach 17-1981, pp. 6-7}.
  7. The number of non-rational subfields of a function field.
    Algebraische Zahlentheorie (W. Jehne, H. W. Leopoldt, P. Roquette), Oberwolfach, 9-15 August 1981.
    {Tagungsbericht Oberwolfach 35/1981, p. 11}.
  8. Thetafunktionen mehrerer Variablen.
    [Theta functions of several variables]
    AG Geyer-Harder: p-adische Uniformisierung (L. Gerritzen, M. van der Put), Oberwolfach, 12-17 April 1982.
    {Tagungsbericht Oberwolfach 15/1982, pp. 3-4}.
  9. Height pairings on curves.
    Conference on the Theory of Numbers, University of Alberta, Edmonton, 28-30 April 1983.
    {Rocky Mt. J. 15 (1985), pp. 417-449}.
  10. ``Real - analytic'' functions on nonarchimedean curves.
    p-adic Function Theory and Analysis (Y. Amice, L. Gerritzen), Oberwolfach, 10-16 February 1985.
    {Tagungsbericht Oberwolfach 9/1985, pp. 19}.
  11. Height pairings on curves.
    Journées arithmétiques, Besançon (France), 24-28 June 1985.
  12. Arithmetische Flächen and Potentialtheorie.
    [Arithmetic surfaces and potential theory]
    Algebraische Zahlentheorie (W. Jehne, H.W. Leopoldt, P. Roquette), Oberwolfach, 3-9 August 1986.
    {Tagungsbericht Oberwolfach 35/1986, pp. 14-16}.
  13. Idempotent relations and factors of Jacobians.
    78th Ontario Math Meeting, Toronto, 7 February 1987.
  14. Potential theory on curves.
    International Number Theory Conference (J.-M. De Koninck, C. Levesque), Québec, 5-18 July 1987.
    {Théorie des Nombres/Number Theory, W. de Gruyter, Berlin, 1989, pp. 475-543}.
  15. Potential theory on curves.
    OSU - Denison Mathematics Conference (J. S. Hsia), Denison OH, USA, 26-27 February 1988.
  16. Idempotent relations and invariants of algebraic varieties.
    First Conference of the Canadian Number Theory Association (R. A. Mollin), Banff, 17-27 April 1988.
  17. Arithmetic intersection theory.
    Algebraische Zahlentheorie (W. Jehne, H.W. Leopoldt, P. Roquette), Oberwolfach, Germany, 7-13 August 1988.
    {Tagungsbericht Oberwolfach, 35/1988, p. 10}.
  18. Green's functions on non-archimedean Riemann surfaces.
    AMS Meeting, Special Session on Arithmetic Intersection Theory. (H. Gillet), Chicago, 19-20 May 1989.
  19. Green's functions on non-archimedean Riemann surfaces.
    p-adic Analysis (F. Baldassarri, B. Dwork, S. Bosch), Trento, Italy, 28 May - 3 June 1989.
  20. Curves of genus two with reducible Jacobians.
    Second Conference of the Canadian Number Theory Association (D. Boyd), Vancouver, 20-26 August 1989.
  21. Kurven vom Geschlecht 2 mit elliptischen Differentialen.
    [Curves of genus 2 with elliptic differentials]
    Algebraische Zahlentheorie (W. Jehne, H. W. Leopoldt, P. Roquette), Oberwolfach, Germany, 12-18, August 1990.
    {Tagungsbericht Oberwolfach, 34/1990, pp. 7-8}.
  22. Curves of genus 2 with elliptic differentials and the Height Conjecture for elliptic curves.
    Conference on Finiteness Theorems in Number Theory (G. Frey), Essen, Germany, 12-15 March 1991.
    {Inst. Exp. Math. Essen, Preprint No. 18-1991, pp. 30-39}.   See also Errata et Addenda.
  23. Ends of metric spaces and arithmetic intersection theory.
    Algebraische Zahlentheorie (G. Frey, H.W. Leopoldt, P. Roquette), Oberwolfach, 2-8 August 1992.
    {Tagungsbericht Oberwolfach, 34/1992, pp. 12-13}.
  24. Abelian varieties over C and Theta-divisors.
    Advanced Workshop on Arithmetic Algebraic Geometry (A. Assadi, U. Jannsen, N. Schappacher), International Centre for Theoretical Physics, Trieste, Italy, 31 August - 11 September 1992.
    {ICTP Lecture Notes SMR. 637/34, 47 pp.}.
  25. Discriminants and regulator relations.
    Conference on Algebra and Number Theory (G. Frey, J. Ritter, H. Stichtenoth, E. Viehweg) Essen, Germany, 2-4 December 1992.
    {Algebra & Number Theory, W. de Gruyter, 1994, pp. 43-135}.
  26. Hermitian R[G]-modules and class number relations.
    Seaway Number Theory Conference, University of Toronto, Toronto, Ontario, 28-29 May 1993.
  27. The Noether formula.
    Advanced Workshop on Arithmetic Algebraic Geometry II, Ain Shams University, Cairo, Egypt, 4-15 September 1993.
    Lecture Notes (distributed to conference participants)
  28. Heights on abelian varieties and the theorem of Mordell-Weil.
    Advanced Workshop on Arithmetic Algebraic Geometry II, Ain Shams University, Cairo, Egypt, 4-15 September 1993.
    Lecture Notes (distributed to conference participants)
  29. Conjectural applications of arithmetic surfaces to number theory.
    Advanced Workshop on Arithmetic Algebraic Geometry II, Ain Shams University, Cairo, Egypt, 4-15 September 1993.
    Lecture Notes (distributed to conference participants)
  30. Hermitian ZG-modules and Brauer's Class Number Relation.
    Conference on L-functions (M. Kolster, V. Snaith), The Fields Institute, Waterloo, Ontario, 21-25 March 1994.
  31. Curves with elliptic differentials and the height conjecture for elliptic curves.
    Arithmetic Algebraic Geometry (A. Parshin, L. Szpiro), Luminy, France, 22-28 May 1994.
  32. Curves of genus 2 and the height conjecture for elliptic curves.
    International Conference on Arakelov Theory (U. Jannsen, N. Schappacher), Max-Planck Institute, Bonn, Germany, 1-7 June 1994.
    {Max-Planck Institute Preprints No. 1994-50, 3pp.}.
  33. Homology theory of Riemann surfaces.
    AG Oberwolfach on Boundedness of Torsion of Elliptic Curves over Number Fields (G. Frey, L. Merel), Oberwolfach, Germany, 9-15 October 1994.
    {Tagungsbericht Oberwolfach 43/1994, p. 12}.
  34. Modular Galois representations and curves of genus 2.
    Seaway Number Theory Conference (K. Williams), Carleton University, Ottawa, 9-10 June 1995.
  35. The construction of genus 2 covers of elliptic curves.
    Galois Workshop (D. Harbater), University of Pennsylvania, Philadelphia, USA, 20-22 October 1995.
  36. Diagonal quotient surfaces.
    Conference on Arithmetic Algebraic Geometry (H. Esnault, E. Viehweg, G. Frey), Institute for Experimental Mathematics, Essen, Germany, 21-24 November 1995.
  37. Applications of diagonal quotient surfaces to a problem of Mazur.
    Conference on Arithmetic Algebraic Geometry (H. Koch, J. Kramer, E.-W. Zink), Berlin, Germany, 21-26 March, 1996.
    {Max-Planck Institute für Mathematik Bonn Preprint No. 1996-51, 5pp.}
  38. Applications of diagonal quotient surfaces to a problem of Mazur.
    Conference on Number Theory (B. Burgess, I. Fesenko), Nottingham, England, 13-16 April, 1996.
  39. The Hecke algebra and modular representations.
    AG Oberwolfach on the Shimura-Taniyama Conjecture (G. Faltings, G. Frey), Oberwolfach, Germany, 7-11 October 1996
    {Tagungsbericht Oberwolfach 38/1996, p. 3}.
  40. Diagonal quotient surfaces and a problem of Mazur.
    CMS Winter Meeting, London Ontario, 7-11 December 1996.
  41. Diagonal quotient surfaces and a question of Mazur.
    Algebraic Number Theory (C. Deninger, G. Frey, P. Schneider, A. Scholl), Oberwolfach, Germany, 20-26 July 1997.
    {Tagungsbericht Oberwolfach /1997, p. }.
  42. Public Key Cryptography and Arithmetic Geometry.
    The Lorne Campbell Conference on Communications (B. Erdahl, F. Alajaji, S. Blostein), Queen's University, Kingston, 1 August 1997.
  43. Diagonal quotient surfaces and a question of Mazur.
    Number Theory and Arithmetical Geometry: Arithmetical Applications of Modular Forms (G. Frey, J. Bost), San Feliu de Guixols, Spain, 24-29 October 1997.
    Lecture (overhead slides)
  44. Mazur's question for mod 11 Galois representations.
    ICM-1998 Satellite Conference on Algebraic and Arithmetic Geometry (H. Esnault, G. Frey, E. Viehweg), Universität Essen, 10-14 August 1998. Lecture (overhead slides)
  45. Mazur's question for mod 11 Galois representations.
    Workshop on Algebraic Modular Forms and Modular Forms mod p (H. Darmon, M. Savin), CRM, University of Montreal, Montreal, 1-7 October 1998.
    Lecture (overhead slides)
  46. Unramified Galois covers of curves over number fields.
    Rosenfest: Conference in Honour of M. Rosen's 60th birthday (J. Silverman, J. Hoffstein), Brown University, Providence, RI, USA; 5-6 March 1999.
  47. Curves with an infinite K-rational geometric fundamental group.
    AMS Conference, Special Session on Galois Theory (J. Thompson, H. Völklein). University of Florida, Gainesville, Florida, 12-13 March 1999.
    Lecture (overhead slides)
  48. Curves with an infinite K-rational geometric fundamental group.
    Workshop on Arithmetical Algebraic Geometry (M. Goresky, K. Murty),CRM, Montreal, 14-18 May 1999.
  49. Unverzweigte Galoissche Überlagerungen von Kurven über Zahlkörpern.
    [Unramified Galois covers of curves over number fields]
    Deutsche Math. Ver. (DMV) Jahrestagung, Sektion Zahlentheorie, University of Mainz, Mainz, Germany, 5-11 September 1999.
  50. p-adic representations of the K-rational geometric fundamental group.
    Galois Actions and Geometry (P. Debes, H. Nakamura, A. Tamagawa), Math. Sci. Research Institute (MSRI), Berkeley, 11-15 October, 1999.
    Lecture (overhead slides)
  51. The state of the art of elliptic curve cryptography.
    CITO Conference: Layers of Security, CITO, Ottawa, 3 February, 2000.
    Lecture (overhead slides)
  52. Equivariant Atkin-Lehner Theory.
    Mini Workshop on Arithmetic Geometry (G. Frey), Inst. Exp. Math., Univ. Essen, 4-6 June 2000.
    Lecture (overhead slides)
  53. The Hurwitz space of genus 2 covers of an elliptic curve.
    AMS Conference, Special Session on Groups and Covering Spaces in Algebraic Geometry (M. Fried, H. Völklein), University of California, Irvine, 10-11 November 2001.
    Lecture (overhead slides)
  54. Modular Diagonal Quotient Surfaces.
    CRM Workshop on Hilbert Modular Varieties (H. Darmon, E. Goren), Far Hills Hotel (near Montreal), 3-6 January 2002.
    Lecture (overhead slides)
  55. The Hurwitz space of genus 2 covers of an elliptic curve.
    CMS Summer Conference, Special Session on Arithmetic Geometry, Université Laval, Québec, 15-17 June 2002.
    Lecture (overhead slides)
  56. The class number relations of Kronecker, Gierster and Hurwitz.
    CMS Summer Conference, Special Session on Number Theory, Université Laval, Québec, 15-17 June 2002.
    Lecture (overhead slides)
  57. Hurwitz spaces of covers of an elliptic curve.
    Quebec-Maine Conference Université Laval, Québec, 12-13 October 2002.
    Lecture (overhead slides)
  58. Applications of the Hurwitz space H_{E/K,N}.
    BIRS Workshop on Fundamental Groups. BIRS (Banff Center), Banff, Alberta, 06-20 September 2003.
  59. The number of covers of an elliptic curve.
    AMS Conference, Special Session on Group Actions on Curves. University of North Carolina, Chapel Hill, NC 24-25 October 2003.
    Lecture (overhead slides)