Leavel, Hugh Rodman
McGraw-Hill, 1958
Buku Teks
Donaldson, R. J.
MTP Press , 1983
Buku Teks
Penalver, Rafael A.
Arco Publishing, Inc., 1981
Buku Teks
Penalver, Rafael A.
Arco Publishing, 1984
Buku Teks
editors, John M. Last, Robert B. Wallace ; associate editors, Elizabeth Barrett-Connor [and others]
Appleton & Lange, 1992
Buku Referensi