Benton, Allen H., author
Burgess Publishing Company, 1972
Buku Teks
Benton, Allen H., author
Tata McGraw-Hill, 1976
Buku Teks
Smith, Robert Leo, author
Harper Collins, 1990
Buku Teks
Smith, Robert Leo, author
Benjamin Cummings, 2001
Buku Teks
Brewer, Richard, author
Saunders College Publishing, 1982
Buku Referensi