Shelly Rodgers and Esther Thorson
Routledge, 2012
Buku Teks SO
Moriarty, Sandra E. (Sandra Ernst)
Prentice-Hall International, 1991
Buku Teks SO
Sissors, Jack Z.
NTC Businness Books, 1993
Buku Teks
Sissors, Jack Z.
NTC Businness Books, 1993
Buku Teks SO
Duffy, Ben
Prentice-Hall, 1957
Buku Teks SO