Hey, L.
Sie Isaac Pitman, 1972
Buku Teks
Brownlee, O.H. (Oswald Harvey), 1917-
Prentice-Hall, 1954
Buku Teks
Herber, Bernard P.
Richard D. Irwin, Inc, 1971
Buku Teks
Due, John F.
Richard D. Irwin, Inc., 1969
Buku Teks
edited by Stanley L. Winer
Edward Elgar, 2002
Buku Teks