- document
- Stapersma, D. (author), Kuijpers, W. (author), Voormolen, J.R. (author) other 1997
- document
- Boomstra, A. (author), Wilgenhof, J.D. (author), Kuijpers, W. (author) other 1997
- document
- Boonstra, H. (author), Wilgenhof, J.D. (author), Kuijpers, W. (author) other 1997
- document
- Beenen, M. (author), Holterman, M.M. (author), Klimp, T. (author), Kuijpers, W. (author), Zwets, B. (author) other 1994