Echavarria, Jose Medina, author
New York, N.Y., Unesco
Buku Teks
Powelson, John P., author
McGraw-Hill , 1964
Buku Teks
Powelson, John P., author
McGraw-Hill , 1964
Buku Teks
Vallier, Ivan, author
Prentice-Hall, 1970
Buku Teks
Cochran, Thomas C., author
Macmillan, 1947
Buku Teks