Hewitt, Paul G.
Pearson - Addison Wesley, 2008
Buku Teks
Tillery, Bill W.
McGraw-Hill, Higher Education, 2007
Buku Teks
Merken, Melvin
Saunders College Publishing, 1993
Buku Teks
McCarthy, Francis W.
Allyn and Bacon, 1972
Buku Teks
Harbeck, Richard M.
Holt Rinehart and Winston, 1965
Buku Teks