Baber, Anne
American Management Association, 2007
eBooks
Walker, Robert A.
The Dryden Press, 1953
Buku Teks
Cohen, Morris L.
West Publishing Company, 1983
Buku Teks
Babbie, Earl R.
Wadsworth and Cengage Learning, 2013 (Student Edition)
Buku Teks
Babbie, Earl R.
Wadsworth and Cengage Learning, 2013 (International edition)
Buku Teks