- document
- Verberg, R. (author), de Schepper, I.M. (author), Cohen, E.G.D. (author) journal article 2000
- document
- Verberg, R. (author), de Schepper, I.M. (author), Cohen, E.G.D. (author) journal article 1997
- document
- de Schepper, I.M. (author), Cohen, E.G.D. (author), Verberg, R. (author) journal article 1996