Russell, Anne
Prentive-Hall, 1982
Buku Teks
Lutz, Vera
Oxford University Press , 1962
Buku Teks
Steiner, George A. (George Albert), 1912-, author
McGraw-Hill, 1953
Buku Teks
Clynes, A. J.
International Development Program of Australian Universities and Colleges Limited, 1985
Buku Teks
Gregor, Howard F., author
Van Nostrand Reinhold, 1963
Buku Teks