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- Weide, J. van der (author), Boer, K. den (author), Burger, A.M. (author), Pilarczyk, K.W. (author), Kenter, C.J. (author), Seijffert, J.J.W. (author) report 1982
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- Boer, K. den (author) report 1982
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- Boer, K. den (author), Kenter, C.J. (author) report 1981