Crano, William D., author
Lawrence Erlbaum Assossiate, 2002
Buku Teks
Babbie, Earl, author
Thomson/Wadsworth, 2004
Buku Teks
Goode, William J., author
McGraw-Hill, 1952
Buku Teks
Blalock, Hubert M., author
Prentice-Hall, 1970
Buku Teks
by Claire Selltiz [and others]
Holt, Rinehart and Winston, 1959
Buku Teks