Lederer, William J
W W Norton, 1954
Koleksi Publik
Writer's Digest Bokks, 1994
Buku Teks
Yates, Edward D., author
Contemporary Publishing Company, 1981
Buku Teks
Oberlin, Loriann Hoff, author
[American Management Association, ], 2004
eBooks
Dent, 1958
Koleksi Publik