APA

Lundberg D. E., Lundberg C., . (1993). International travel and tourism. New York: Wiley.

Chicago

Lundberg Donald E, Lundberg Carolyn, . 1993. International travel and tourism. New York: Wiley.

Harvard

Lundberg D. E., Lundberg C., . (1993). International travel and tourism. New York: Wiley.

MLA

Lundberg Donald E, Lundberg Carolyn, . International travel and tourism. New York: Wiley. 1993.