Crowder, Richard
Twayne Publisher, 1964
Buku Teks
Shevell, Richard S.
Prentice-Hall, 1983
Buku Teks
Nixon, Richard, author
Warner Books, 1982
Buku Teks
Bell, Richard
The Edinburgh University Press , 1953
Buku Teks
Wheeler, Richard S.
Cornell University, 1970
Buku Teks