Wall, Robert E.
NC Press, 1983
Buku Teks
Shannon, Robert E.
John Wiley & Sons, 1980
Buku Teks
Fischer, Robert E., author
McGraw-Hill, 1980
Buku Teks
Storry, Richard, 1913-1982, author
Greenwood Press,, 1957
Buku Teks
Wade, Mason
Macmillan of Canada, 1956
Buku Teks