Lauterbach, Richard E.
Harper & Brother Publishers, 1945
Buku Teks
Deshmukh, B. G
HarperCollins Publishers India a joint venture with India Today Group, 2004.
Buku Teks
Rosefielde, Steven
Cambridge University Press, 2017
Buku Teks
Heisterkamp, A.H.T.
Gouda Quint bv., 1983
Buku Teks
Salisbury, Harrison E.
Harrison, 1969
Buku Teks