- document
- Blauw, A.N. (author), Los, F.J. (author), Kranenborg, E.J. (author), Boon, J.G. (author) report 1999
- document
- Smits, J.G.C. (author), Bokhorst, M. (author), Brinkman, A.G. (author), Herman, P.M.J. (author), Ruardij, P. (author), Sonneveldt, H.L.A. (author), Tol, M.W.M. van der (author) report 1997