Oxford Universikty Press , 1956
Buku Teks
Kirkpatrick, Charles A.
Science Research Associates , 1974
Buku Teks
Russ, Frederick A.
Little, Brown & Co., 1982
Buku Teks
Pigors, Paul
McGraw-Hill , 1969
Buku Teks
Pigors, Paul
McGraw-Hill Book Company, Inc, 1956
Buku Teks