Carlyle, Thomas, author
E.P. Dutton, 1955
Buku Teks
Carpenter, Catrine, author
McGraw-Hill, 2004
Buku Teks
Mellion, Morris B., author
Hanley & Belfus, 1994
Buku Teks
Mangan, James T., author
Prentice-Hall, 1963
Buku Teks
Jarvis, Helen, author
Prentice-Hall, 2001
Buku Teks