APA
Cruz Z. L., . (1999). Principles and ethics of tour guiding. [Place of publication not identified]: Rex Book Store.
Chicago
Cruz Zenaida L, . 1999. Principles and ethics of tour guiding. [Place of publication not identified]: Rex Book Store.
Harvard
Cruz Z. L., . (1999). Principles and ethics of tour guiding. [Place of publication not identified]: Rex Book Store.
MLA
Cruz Zenaida L, . Principles and ethics of tour guiding. [Place of publication not identified]: Rex Book Store. 1999.