Lampert, Hope, author
Atheneum, 1986
Buku Teks
Covington, Howard E.Jr.
Univesity of North Carolina Press. , 1993
Buku Teks
Mueller, F. W.
McGraw-Hill Book Company, Inc., 1951
Buku Teks
Ranlett, John G., author
John Wiley and Sons, 1969
Buku Teks
Ranlett, John G., author
John Wiley and Sons, 1969
Buku Teks
Steiner, William Howard, author
Henry Holt, 1956
Buku Teks