Loll, Leo M.
Prentice-Hall, 1973
Buku Teks
Yevenko, Ivan Andreevich
Foreign Languages Publishing House , [1962]
Buku Teks
F. Damian Leo
Kluwer, 1978
Buku Teks
Buscaglia, Leo
Charles B. Slack, 1982
Buku Teks
Schnore, Leo F.
The Free Press, 1965
Buku Teks