Ranz, John H.
W.H. Anderson Co., 1966
Buku Teks
Gates, Jean Key, author
McGraw-Hill, 1974
Buku Referensi
De Vries, Mary Ann, author
Prentice-Hall, 1991
Buku Referensi
Isaac, Katherine
St. Martin's Press, 1977
Buku Teks
Whiteman, Lily Madeleine, author
[American Management Association;, ], 2008
eBooks