- document
- Tacken, M. (author), Marcellini, F. (author), Mollenkopf, H. (author), Ruopilla, I. (author) book 1999
- document
- Teule, R. (author), Van der Heijde, J. (author) book 1994
- document
- Hoenderdos, T. (author), Vermeeren, J. (author) book 1990
- document
- Heeger, H. (author) book 1990