- document
- Pen, C.J. (author) book 1998
- document
- Van Miltenburg, A.I.M. (author), Hakfoort, I.R. (author) book 1992
- document
- Steijger, R.C.A. (author), Kooijman, D.C. (author) book 1991
- document
- Wassenberg, F. (author) book 1991
- document
- Priemus, H. (author) book 1989