Urhausen, J. (2008). Tourism in Europe: Does age matter? Statistics in focus: Industry, trade and services.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रUrhausen, Julia. "Tourism in Europe: Does Age Matter?" Statistics in Focus: Industry, Trade and Services 2008.
एमएलए (8वां संस्करण) प्रशस्ति पत्रUrhausen, Julia. "Tourism in Europe: Does Age Matter?" Statistics in Focus: Industry, Trade and Services, 2008.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.