Wells, S.J.
Cambridge University Press , 1964
Buku Teks
Harfiyah Widiawati, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2003
UI - Tesis (Membership)
University of California Press, 1966
Buku Teks
Artikel Jurnal
The National Library of The Philippines
The National Library of The Philippines, 1989
Buku Referensi