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- van Leeuwen, Ger (author) conference paper 1972
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- van Leeuwen, Ger (author) report 1972
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- van Leeuwen, Ger (author) report 1971
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- van Leeuwen, Ger (author) report 1971
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- van Leeuwen, Ger (author) report 1970
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- van Leeuwen, Ger (author) report 1970
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- van Leeuwen, Ger (author) report 1969
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- van Leeuwen, Ger (author), Glansdorp, C.C. (author) report 1966
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- van Leeuwen, Ger (author) report 1964
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- van Leeuwen, Ger (author) report 1963
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- van Leeuwen, Ger (author) report 1963
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- van Leeuwen, Ger (author) report 1962
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- van Leeuwen, Ger (author) report 1962
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- van Leeuwen, Ger (author) report 1961
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- van Leeuwen, Ger (author), Thiecke, H.P.J. (author) report 1960