Littlewood, William, author
Cambridge University Press, 1998
Buku Teks
Hazen, Kirk, author
Massachusetts : Wiley Blackwell, 2015
Buku Teks
Fromkin, Victoria A., author
Holt, Rinehart and Winston, 1981
Buku Teks
Montgomery, Martin, author
Routledge, Taylor & Francis Group, 2008
Buku Teks
Ralph Fasold; Jeff Connor-Linton
Cambridge University Press , 2006
Buku Teks