editor, Bert Kaplan
Harper & Row, 1961
Buku Teks SO
Beamer, Linda
[publisher not identified], [date of publication not identified]
Buku Teks
Tokyo : Japan Publication Trading
Majalah, Jurnal, Buletin
Purnell, Larry D.
F.A. Davis, 2005
Buku Teks
Pavlik, Cheryl
[publisher not identified], [date of publication not identified]
Buku Teks