Lapin, Lawrence L.
Harcourt Brace Jovanovich, 1978
Buku Teks
Lapin, Lawrence L.
Harcourt Brace Jovanovich, 1990
Buku Teks
Conover, W.J.
Wiley, 1983
Buku Teks
Williams, Frederick
Harcourt Brace Jovanovich College Publishers, 1992
Buku Teks
Runyon, Richard P.
Ill. Richard D. Irwin , 1982
Buku Teks