- document
- Gilding, B.H. (author), Kroot, M.P.J.M. (author), Wesseling, J.W. (author), Rooij, N.M. de (author), Streng, J. (author), Bril, J. (author), Postma, L. (author) report 1985
- document
- Pagee, J.A. van (author), Postma, L. (author), Leussen, W. van (author), Villars, M.T. (author), Markus, A.A. (author) report 1994