Davidoff, Philip G. Worldwide tours : a travel agent's guide to selling tours / Philip G. Davidoff, Doris S. Davidoff. - Englewood Cliffs, NJ. : Prentice Hall, 1990 - 82 p. ; 28 cm. ISBN: 0139648917 Subjects--Topical Terms: Package toursTravel agents Dewey Class. No.: 338.4791 / D249W 1990