2010
Artikel Jurnal
Stratmann, Francus Henry
London Oxford University Press 1958
Buku Referensi
New York Funk and Wagnalls Company 1955
Buku Referensi
New York Funk and Wagnalls 1958
Buku Referensi
Cowan, H.K.J (Hendrik Karel Jan)
Martinus Nijhoff, , 1965 [1966]
Buku Teks