- document
- Barens, L.M. (author), Van Borselen, R.G. (author), Fokkema, J.T. (author), Van den Berg, P.M. (author) conference paper 1995
- document
- Fokkema, J.T. (author), Van Borselen, R.G. (author), Van den Berg, P.M. (author) conference paper 1994
- document
- Van Borselen, R.G. (author), Thorbecke, J. (author), Fokkema, J.T. (author), Van den Berg, P.M. (author) conference paper 1991