edited by Francis M. Hult and David Cassels Johnson
Wiley Blackwell, 2015
Buku Teks
Mollett, Amy
SAGE, 2017
Buku Teks
Leedy, Paul D.
Pearson Education, 2005
Buku Teks SO
Sophie Laws, Caroline Harper, Nicola JOnes, Rachel Marcus
SAGE, 2013
Buku Teks
French, Sally
Butterworth-Heinemann, 2001
Buku Referensi