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Wiley, 1980
Buku Referensi
Stein, J. Stewart, author
John Wiley & Sons, 1993
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Peterson, Ralph
S & A Wheeler-Whitfield, 1972
Buku Teks
editor in-chief, Seymour Kurtz
New York Times, c1969
Buku Referensi
Brant, Irving
Bobbs-Merrill Company,Inc., 1953
Buku Teks