Lucken, Karol M.
Routledge, Taylor & Francis Group, 2017
Buku Teks
Wright, Burton
W.B. Saunders, 1978
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Barnes, Harry Elmer
Alumni, 1975
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Hough, Michael
Research Office Research and Statistics Directorate, 1998
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Tappan, Paul W.
McGraw-Hill, 1960
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