John Flowerdew, Matthew Peacock
Cambridge University Press, 2001
Buku Teks
Deny Arnos Kwary
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2004
UI - Tesis Membership
Tomasowa, Francien Herlen
Universitas Brawijaya , 2005
Buku Teks
Quirk, Randolph
English Language Book Society/Longman, 1989
Buku Teks
Scobie, Janet I.
George Allen and Unwin, 1959
Buku Teks