1. Progress in information technology and tourism management: 20 years on and 10 years after the Internet—The state of eTourism research
2. Newswire US 2005 Online Travel Purchases Split Evenly Between Travel Agencies and Suppliers Newswire US 2005 Online Travel Purchases Split Evenly Between Travel Agencies and Suppliers PR
3. Zebua F. 2018. Laporan DailySocial: Survey Online Travel Agencies (OTA) 2018 (in Bahasa Indonesia) Zebua F. 2018. Laporan DailySocial: Survey Online Travel Agencies (OTA) 2018 (in Bahasa Indonesia)
4. Tekno Kompas. 2018. Indonesia's Largest 'Online Travel' Market in Southeast Asia (in Bahasa Indonesia) Tekno Kompas. 2018. Indonesia's Largest 'Online Travel' Market in Southeast Asia (in Bahasa Indonesia)
5. eMarketer. 2005. Which ways is the travel industry headed? eMarketer. 2005. Which ways is the travel industry headed?