edited by Jurgen Ruland, Maria-Gabriela Manea and Hans Born
Springer, 2013
eBooks
Schwarz, Adam
Allen & Unwin, 1994
Buku Teks SO
Silverstein, Josef
Cornell University Press, 1977
Buku Teks SO
Finer, S.E.
Frederick A. Praeger, 1962
Buku Teks SO
Indonesia. Directorate General of Tourism
Wahyu Promospirit, 1990
Buku Referensi