Gravetter, Frederick J., author
Thomson Wadsworth, 2007
Buku Teks
Kaplan, Robert M., author
Allyn and Bacon , 1987
Buku Teks
Kuzma, Jan W., author
Mayfield Publ., 1984
Buku Teks
Siegel, Sidney, author
McGraw-Hill, 1956
Buku Teks
Blalock, Hubert M., author
McGraw-Hill, 1960
Buku Teks