Okun, Barbara F., author
Cengage Learning, 2015
Buku Teks
Ellis, Anthony, author
Routledge, 2017
Buku Teks
edited by Ray Woolfe, Windy Dryden, Sheelagh Strawbridge
Sage Publications, 2003
Buku Referensi
Wang, Qing, 1985-, author
Routledge, 2018
Buku Teks
Arbuckle, Dugald S., author
Allyn and Bacon, 1961
Buku Teks