Stebbins, Robert A.
Sage, 2001
Buku Teks
edited, Bridget Somekh, Cathy Lewin
Sage Publications , 2005
Buku Teks
Polgar, Stephen
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Buku Teks
Gravetter, Frederick J.
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Buku Teks
Gravetter, Frederick J.
CT Cengage Learning, 2016
Buku Teks