- document
- Boersma, W. (author) master thesis 2014
- document
- Boersma, W. (author) master thesis 2014
- document
- Boersma, J.S. (author) master thesis 1992
- document
- Boersma, P.D. (author) master thesis 1991
- document
- Boersma, P.D. (author) master thesis 1990
- document
- Boersma, A.J. (author) master thesis 1988