Simorangkir, J.C.T., author
Gunung Agung, 1984
Buku Teks
Siburian, Lawrence Tp, author
Universitas Indonesia, 1983
UI - Skripsi (Membership)
Titik Triwulan Tutik, author
Kencana Prenada Media Group, 2010
Buku Teks
Padmo Wahyono, author
Academica , 1980
Buku Teks
Julianti Tri Astuti, author
1989
UI - Skripsi (Membership)