Mather, Peter, author
South Australia, 1984
Buku Teks
M.A. Yunita Triwardani Winarto, author
LAP Lambert Academic Publishing, 2011
Buku Teks
Gordon, Adam, 1964- , author
American Management Association, 2008
eBooks
Wilson, George P., author
F.S. Crofts, 1947
Buku Teks
Reader's Digest Service, 1987
Buku Teks