United Nations , 1987
Buku Teks
Lawson, Edward, author
Taylor and Francis, 1991
Buku Referensi
Criddle, Evan J, author
Cambridge University Press, 2016
eBooks
Kaligis, O.C. (Otto Cornelis), 1942-, author
O.C. Kaligis & Associates, 2008
Buku Teks
Kaligis, O.C. (Otto Cornelis), 1942-, author
O.C. Kaligis & Associates, 2008
Buku Teks