Siagian, Sondang P., author
Bumi Aksara, 2004
Buku Teks
Siagian, Sondang P., author
[publisher not identified], 1998
Buku Teks
Siagian, Renville, author
Gadjah Mada University press, 1997
Buku Teks
Tampubolon, Daulat Purnama, author
Gramedia Pustaka Utama, 2001
Buku Teks
Koontz, Harold, author
Erlangga, 1989
Buku Teks