Brachet, Michelle
Murray Books (Australia, 2012
Buku Referensi
Saricks, Joyce G.
[American Management Association, ], 2009
eBooks
Sharpe, Leslie T.
Camberidge University Press , 1994
Buku Teks
Jacobs, Hayes B.
Writer`s Digest Books, 1968
Buku Teks
Rice, Thomas Jackson
Gale Research Company, 1983
Buku Referensi