Rosenbloom, David H., author
McGraw-Hill Education, 2015
Buku Teks
Reynolds, Lloyd G., author
Prentice-Hall, 1982
Buku Teks
Player, Macka
West Publishing, 1992
Buku Teks
Cook, Franklin Henry
Macmillan, 1951
Buku Teks
Stanley, Joyce, 1901-, author
Warren, Gorham and Lamont, 1971
Buku Teks