McGraw-Hill , 1960
Buku Teks
Markland, Robert E.
John Wiley & Sons, 1983, 1989
Buku Teks
Fischer, Robert E., author
McGraw-Hill , 1964
Buku Teks
Ball, Robert E.
Routledge and Kegan Paul, 1983
Buku Teks
Keeton, Robert E., author
West Pub. Co., 1960
Buku Teks