Massachusetts Institute of Technology | California Institute of Technology | Art Institute of Chicago | Institute for Advanced Study | American Institute of Architects | Georgia Institute of Technology | Rensselaer Polytechnic Institute | Rochester Institute of Technology | Franklin Institute | Royal Institute of Technology | Pasteur Institute | Institute of Contemporary Arts | California Institute of the Arts | Institute of Electrical and Electronics Engineers | British Film Institute | Pratt Institute | National Cancer Institute | Virginia Military Institute | Cato Institute | Australian Institute of Sport | Illinois Institute of Technology | Curtis Institute of Music | American Institute of Aeronautics and Astronautics | Royal Institute of British Architects | National Institute of Standards and Technology | Monterrey Institute of Technology and Higher Education | Institute of Physics | List of Monterrey Institute of Technology and Higher Education faculty | Weizmann Institute of Science | Indian Institute of Science |
He was scientific assistant and university lecturer at Department of Limnology, University of Oslo, from 1960 to 1966; research scientist at Freshwater Institute, Winnipeg, Manitoba, Canada from 1966-1977; and professor of systematic zoology in the Museum of Zoology at the University of Bergen from 1977 to his retirement in 2006.He specialized in aquatic Diptera, especially Chironomidae and Chaoboridae.