by Westerling F.J, Schijvens E.P.H.M
Published in Rapport. Sprenger Instituut (Netherlands). no. 2262 (1984)

by Damen P.M.M, Hak P.S, Rol W, Westerling F.J
Published in Rapport. Sprenger Instituut (Netherlands). no. 2272 (1984)

by Westerling, F.J. (Sprenger Inst., Wageningen (Netherlands)), Jansen, H.W
Published in Rapport. Sprenger Instituut (Netherlands) (1988)

by Damen, P.M.M. (Sprenger Inst., Wageningen (Netherlands)), Hak, P.S, Rol, W, Westerling, F.J
Published in Rapport. Sprenger Instituut (Netherlands) (1984)