Abernathy, Charles F.
St. Paul Minn., 2000
Buku Teks
Bonnicksen, Andrea L
Mayfield Publishing Company, 1982
Buku Teks SO
University of Souther California Press, 1980
Buku Teks SO
Way, H. Frank
McGraw-Hill, 1981
Buku Teks SO
Martinus nNijhoff Publisher, 1982
Buku Teks