- document
- Van de Graaf, A.V. (author), Hendriks, M.A.N. (author), Rots, J.G. (author) conference paper 2009
- document
- Van de Graaf, A.A. (author), Mulder, A. (author), Slijkhuis, H. (author), Robertson, L.A. (author), Kuenen, J.G. (author) conference paper 1990