Mitford, Jessica
Simon and Schuster, 1963
Buku Teks
Temes, Roberta, author
American Management Association, 2009
eBooks
Sitompul, A. R Adelany, author
2001
UI - Skripsi Membership
Routledge, 1997
Buku Teks
William J. Buckley, Karen S. Feldt, editor and introduction
McGraw-Hill, 2013
Buku Teks