edited by Raymond E. Wolfinger
Prentice-Hall, 1966
Buku Teks
Masannat, George S., author
Charlies Scribuner's Sons, 1971
Buku Teks
Woll, Peter, author
Longman , 2001
Buku Teks
Wilfred D. Webb
Thomas Y. Crowell Company, 1961
Buku Teks
Woll, Peter, author
Little, Brown, 1984
Buku Teks