Crawford, Kenneth Grant
University of Toronto Press, 1958
Buku Teks
Dwi Rianisa Mausili, author
Kementerian PPN/Bappenas, 2019
Artikel Jurnal
edited by Leila Kosseim and Diana Inkpen
Springer-Verlag, 2012
eBooks
Dawson, Robert MacGregor
Vancouver The Copp Clark Publshing Co. 1957,
Buku Teks
Oxford University Press, 1956
Buku Teks