Saragih, Ferdinand Dehoutman, author
RajaGrafindo Persada, 2014
Buku Teks
Ward, Richard, author
Prentice-Hall, 1965
Buku Teks
Ward, Richard, author
Prentice-Hall, 1965
Buku Teks
Yeager, Leland B., author
Holt, Rinehart, and Winston, 1968
Buku Teks
Melvin, Michael, author
HarperCollins, 1995
Buku Teks