Cozby, Paul C.
McGraw-Hill, Higher Education, 2008
Buku Teks SO
Gravetter, Frederick J.
Wadsworth, 2012
Buku Teks SO
Cozby, Paul C.
McGraw-Hill, 2003
Buku Teks SO
Ziegenfuss, James T.
Van Nostrand Reinhold Company, 1985
Buku Teks SO
Luchins, Abraham S.
Holt, Rinehart and Winston, 1965
Buku Teks SO