Pasaribu, Ruth Vania Christine , author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2014
UI - Skripsi (Membership)
Rose, Peter I., foreword
Random House, 1964
Buku Teks
Schaefer, Richard T, author
Pearson Education, 2015
Buku Teks
edited by Milton L. Barron
Alfred A. Knoff, 1969
Buku Teks
Bennett, Lerone
Penguin Books, 1969
Buku Teks