Diem Ihsan
Universitas Sriwijaya, 2011
Buku Teks
Cohen, David
Routledge, 2006
Buku Teks
edited by Charles E. Schaefer and Kevin J. O'Connor
John Wiley & Sons, 1982
Buku Referensi
Carmichael, Karla D.
Pearson - Prentice Hall, 2006
Buku Teks
Cruse, Alan
Oxford University Press, 2013
Buku Teks