Howell, D. W. (1993). Passport: An Introduction to the travel and tourism industry (2nd ed.). Cincinnati: South-Western.
استشهاد بنمط شيكاغوHowell, David W. Passport: An Introduction to the Travel and Tourism Industry. 2nd ed. Cincinnati: South-Western, 1993.
MLA استشهادHowell, David W. Passport: An Introduction to the Travel and Tourism Industry. 2nd ed. Cincinnati: South-Western, 1993.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.