- document
- de Haas, Pieter D. (author) master thesis 1999
- document
- de Haas, P.C. (author) master thesis 1990
- document
- de Haas, P.C. (author) master thesis 1990
- document
- de Haas, P.C. (author) master thesis 1990
- document
- de Haas, P. (author) master thesis 1989
- document
- de Haas, J.G.E. (author), Hengst, S. (author), Saurwalt, K.J. (author) master thesis 1984