Saunders, N.F.T. (Norman Frank Tilbury), author
Sir Isaac Pitman & Sons, 1946
Buku Teks
Amrine, Harold T., author
Prentice-Hall, 1975
Buku Teks
by Harold T. Amrine [and others]
Prentice-Hall, 1993
Buku Teks
Davis, Ralph Currier, author
Harper & Row, 1940
Buku Teks
Hopp, Wallace J., author
McGraw-Hill, 2000
Buku Teks