Shaughnessy, John J.
McGraw-Hill, 2006
Buku Teks
Langdridge, Darren
Pearson, 2004
Buku Teks
Kerlinger, Fred Nichols, 1910-
CBS College Publishing, 1986
Buku Teks
Kerlinger, Fred Nichols, 1910-
Harcourt Brace College Publishers, 1973
Buku Teks
Kerlinger, Fred Nichols, 1910-
Holt, Rinehart and Winston, 1964
Buku Teks