Wagner, Lola
Pustaka Sinar Harapan, 1997
Buku Teks
Universitas Indonesia, 2003
UI - Skripsi (Membership)
Wagner,Lola
Buku Teks
Saragi, Tonny Horas
Universitas Indonesia, 1994
UI - Skripsi (Membership)
Universitas Indonesia, 1993
UI - Skripsi (Membership)