Prentice, Richard, author
Routledge, 1993
Buku Teks
Boniface, Priscilla, author
Routledge, 1993
Buku Teks
edited by Michael Hitchcock
Nias Press, 2010
Buku Teks
edited by Wendu Nuryanti
Gadjah Mada University Press, 1997
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