Saxena, H.L.
S. Chand & Co, 1957
Buku Teks
R. Vassilev
Publishing House of the Bulgaria, 1970
Buku Teks
editor, S. Prajudi Atmosudirdjo ...[et al.]
Ghalia Indonesia, 1987
Buku Teks
Griffith University,
Majalah, Jurnal, Buletin
Resnikoff, H.L.
Holt, Rinehart and Winston, 1973
Buku Teks