Gultom, Polman, author
Universitas Indonesia, 1991
UI - Skripsi (Membership)
Universitas Indonesia, 1990
UI - Skripsi (Membership)
Universitas Indonesia, 1992
UI - Skripsi (Membership)
Universitas Indonesia, 1995
UI - Skripsi (Membership)
Damanik, Rachmaihut, author
Universitas Indonesia, 1995
UI - Skripsi (Membership)