Abernathy, Charles F.
St. Paul Minn., 2000
Buku Teks
Bonnicksen, Andrea L
Mayfield Publishing Company, 1982
Buku Teks
University of Souther California Press, 1980
Buku Teks
Way, H. Frank
McGraw-Hill, 1981
Buku Teks
Foster, Steve
Oxford university press, 2012
Buku Teks