Healy, Karen, author
Palgrave Macmillan, 2005
Buku Teks
Cohen, Nathan Edward, author
National Ass. of Workker, 1964
Buku Teks
Cournoyer, Barry R., author
Brooks/Cole Cengage Learning, 2011
Buku Teks
Skidmore, Rex A. (Rex Austin), author
Prentice Hall International, 1991
Buku Teks
Skidmore, Rex A. (Rex Austin), author
Prentice-Hall, 1994
Buku Teks