Starr, Wilmarth H.
American Book Company, 1959
Buku Teks
Publications Bureau for the Ministry of culture: book four (A lesson 1-8),
Multimedia
EPB Publ., 1980
Buku Teks
Educational Publications Bureau for the Ministry of culture: book four (A lesson 1-8),
Multimedia
Fucilla, Joseph G.
Follett Publishing Company, 1964
Buku Referensi