- document
- Winterwerp, J.C. (author), Thoolen, P.M.C. (author) report 1998
- document
- Savornin Lohman, A.A.M. de (author), Postma, L. (author) report 1993
- document
- Boon, J.G. (author), Dekker, E.A. (author), Postma, L. (author), Savornin Lohman, A.A.M. de (author) report 1992
- document
- Taal, W.J. (author) report 1990
- document
- Dorenbos, G.J. (author) report 1987