Keates, J. S., author
John Wiley & Sons, 1973
Buku Teks
Dent, Borden D.
Wm. C. Brown , 1990
Buku Teks
Tomlin, Dana C., author
Prentice-Hall, 1990
Buku Teks
Raisz, Erwin Josephus, 1893-, author
McGraw-Hill, 1948
Buku Teks
Robinson, Arthur H., author
John Wiley & Sons, 1978
Buku Teks