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- Anderegg, P.Y.F. (author), Van Dekkum, R.H. (author), Blom, C. (author), Schulte, A.A. (author), Stoter, C.F. (author), Veldhuizen, F.J.E. (author), Verhoeff, E.J. (author), Vlug, A.N. (author), Blomsma, R.T. (author), Kerstjens, J.H. (author), Lommerse, J.P.H. (author), Rovers, P. (author), De Wolff, J. (author) report 1987