Education: Universities of Leiden and Utrecht, Mathematics and Physics, 1940--49 (with war-time interruptions)
Ph.D. in Mathematics, Leiden, 1949
Regular professorships (Mathematics)
Technical University Delft (Netherlands), 1951-(Jan)1953
University of Wisconsin (Madison), (Feb)1953--64
(Chairman, Program in Applied Mathematics and Engineering Physics, 1956--61)
University of California San Diego (La Jolla), 1964--74
(Chairman, Dept of Mathematics, 1971--73)
University of Amsterdam, 1974--(Jan)93
(Director, Math. Institute, 1980--83)

Temporary and visiting positions
Mathematical Center, Amsterdam, 1947--49
Purdue University, Acad. yrs 1949--51
University of Michigan, Summer 1950
Stanford University, Acad. yr 1961--62 and several summers
Claremont Graduate School, Sep. 1969 -- Jan. 1970
University of Oregon, Summer 1970
Imperial College, London, Acad. yr 1970--71
Technical University Eindhoven, Summer 1971
California Institute of Technology, Spring 1988
Bar-Ilan University (Israel), Spring 1992

Honors and special assignments
Reynolds' award for outstanding teaching of future engineers, University of Wisconsin, 1956
Elected Fellow Amer. Assoc. Adv. Science, 1961
Chairman, American Mathematical Society Summer Research Institute on "Entire functions and related parts of analysis", La Jolla, 1966
Member, KNAW (Royal Netherlands Academy of Arts and Sciences) since 1975
Honorary doctorate, University of Gothenburg (Sweden), 1978
Chairman, Wiskundig Genootschap (Netherlands Mathematical Society), 1982--84
Lester R. Ford Prize (1987) and Chauvenet Prize (1989) for mathematical exposition (Mathematical Association of America)
Elected honorary member, Netherlands Math. Soc., 1998
Honorary member, Amer. Math. Society
Editor or co-editor of various mathematical journals and of conference proceedings at one time or another