Marion Wesley Todd
Macmillan, 1934
Buku Teks
Hyman, Herbert H., author
John Wiley & Sons, 1972
Buku Teks
Fink, Arlene, author
Thousand Oaks : SAGE PUBLIKATION, 2003,
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Fink, Arlene, author
Thousand Oaks : SAGE PUBLIKATION, 2003,
Buku Referensi
Linda P. Bourque, Eve P. Fielder
Thousand Oaks : SAGE PUBLIKATION, 2003,
Buku Referensi