Murray, Jerome T., author
George Allen and Unwin, 1971
Buku Teks
edited by William B. Frakes
Pretice-Hall , 1992
Buku Teks
Spencer, Donald D., author
Charles E. Merrill, 1982
Buku Teks
O`Brien, James A., 1936-, author
Irwin, 1997
Buku Teks
Olson, David Louis, author
McGraw-Hill , 2004
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