APA
Callaghan P., long p. & robinson m. (1994). Travel & Tourism. London: Center for travel.
Chicago
Callaghan Paul, long phil and robinson mike. 1994. Travel & Tourism. London: Center for travel.
Harvard
Callaghan P., long p. and robinson m. (1994). Travel & Tourism. London: Center for travel.
MLA
Callaghan Paul, long phil and robinson mike. Travel & Tourism. London: Center for travel. 1994.
