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- Bedaux, M. (author), Broeksmit, W.B. (author), Broersma, S.A. (author), Emanuels, H.B. (author), Havenaar, D. (author), Herrewiinen, J.B. (author), Hoekstra, H.Y. (author), De Lannoy, M.R.J. (author), Simon, S.B. (author), Welp, F. (author) report 1987