Alexandrescu, Vasile
Military Pub. House, 1985
Buku Teks
Deborin, G.
Progress Publishers, 1979
Buku Teks
Brogan, D.W. (Denis William)
Harcourt, Brace & World, 1963
Buku Teks
Friedrich, Carl J.
Rinehart, 1948
Buku Teks
Thrower, Peter A.
McGraw-Hill, 1996
Buku Teks