Sihombing, Tumpal, author
Bond Research Institute, 2013
Artikel Jurnal
Stonier, Alfred W.
Ghallia Indonesia, 1984
Buku Teks
Dewett, Kewal Krishan
Premier Publishing Co. , 1969
Buku Teks
edited by Masao Ishikura, Seongjin Jeong, Minqi Li
Emerald, 2017
eBooks
Morishima, Michio
Oxford Clarendon Press 1969,
Buku Teks