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- de Heer, Piet W. (author) report 1997
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- de Heer, Piet W. (author) conference paper 1997
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- Vossnack, Ernst (author), Buys, C.T. (author), de Heer, Piet W. (author) report 1997
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- de Heer, Piet W. (author) report 1997
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- de Heer, Piet W. (author) report 1996
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- de Heer, Piet W. (author) report 1995
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- de Heer, Piet W. (author) report 1994
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- de Heer, Piet W. (author) book 1994
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- de Heer, Piet W. (author) conference paper 1994
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- de Heer, Piet W. (author) report 1993
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- de Heer, Piet W. (author) report 1992
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- de Heer, Piet W. (author) report 1992
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- de Heer, Piet W. (author) report 1992
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- de Heer, Piet W. (author) report 1992
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- de Heer, Piet W. (author) report 1992
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- de Heer, Piet W. (author) report 1992
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- de Heer, Piet W. (author) report 1991
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- de Heer, Piet W. (author) report 1991
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- de Heer, Piet W. (author) report 1990
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- de Heer, Piet W. (author) report 1990