Clarke, David L, author
Methuen, 1968
Buku Teks
London : Routledge
Majalah, Jurnal, Buletin
Mongait, Alexander, author
Foreign Languages Publishing House, 1959
Buku Teks
Buku Teks
Kathryn Rountree, Christine Morris, Alan A.D. Peatfield, editor
[Springer, ], 2012
eBooks