Axtell, Roger E.
John Wiley & Sons, 1995
Buku Teks
Doff, Adrian, author
Cambridge University Press, 2010
Multimedia
Doff, Adrian, author
Cambridge University Press, 2010
Multimedia
disusun oleh Sofia Rangkuti-Hasibuan ; editor, Nung Atasana
Gramedia Pustaka Utama, 1992
Buku Teks
Macmillan, 1965
Buku Teks