Bishop, Margaret S.
Charies E Mernill, 1976
Buku Teks
Ramsey, William L., author
Holt, Rinehart and Winston, 1961
Buku Teks
McConnell, David, author
McGraw-Hill, 2010
Buku Teks
Owen, Claudia, author
Brooks/Cole Cengage Learning, 2010
Buku Teks
Beiser, Arthur, author
McGraw-Hill Irwin, 1975
Buku Teks