Parten, Mildred
Haper & Brother, 1950
Buku Teks
Van Duyn, Julia, author
Reston Publishing Company, Inc ., 1975
Buku Teks
Van Duyn, Julia, author
Reston Publishing Company, Inc ., 1975
Buku Teks
Justice, Thomas, author
American Management Association, 2006
eBooks
Jain, Pradeep, author
Jaypee, 2013
Buku Teks