Carison, John G.H.
John Wiley & Sons, 1972
Buku Teks
Newstrom, John W., author
McGraw-Hill, 1975
Buku Teks
Everest, Gordon C.
McGraw-Hill, 1986
Buku Teks
Courtis, John
Arcan , 1992
Buku Teks
Britt, Steuart Henderson, author
McGraw-Hill , 1968
Buku Teks