Manurung, Marina Margaretha
2016
UI - Skripsi (Membership)
Taylor, Benjamin J.
Prentice-Hall, 1987
Buku Teks
Carrell, Michael R.
Prentice-Hall, 2001
Buku Teks
Devinka Adira
Universitas Indonesia, 2018
UI - Skripsi (Membership)
Blanpain, Roger (et.al.)
Cambridge University Press, 2007
Buku Teks