edited by Yiorgos Apostolopoulos, Stella Leivadi and Andrew Yiannakis
Routledge, 1996
Buku Teks
Mill, Robert Christie
Prentice-Hall, 1990
Buku Teks
Candela, Guido
[Springer, ], 2012
eBooks
Universitas Pancasila. Fakultas Pariwisata, {s.a.}
Majalah, Jurnal, Buletin
Inkson, Clare
Sage, 2018
Buku Teks SO