1. Loures, L., Castanho, R.A., Vulevic, A., Naranjo Gómez, J., Cabezas, J., Fernández-Pozo, L.: The Multi-Variated Effect of City Cooperation in Land Use Planning and Decision-making Processes – A European Analysis. In: Urban Agglomerations, pp. 87–106. InTech (2018). ISBN: 978-953-51-5884-4
2. Castanho, R.A.: Sustainable Urban Planning in Transboundary Areas: Analysis of Critical Factors for Territorial Success. Doctoral Thesis University of Extremadura (UEx) Badajoz, Spain, Department of Vegetal Biology, Ecology and Earth Sciences (2017)
3. Koçak, E., Ulucak, R., Şentürk Ulucak, Z.: The impact of tourism developments on CO2 emissions: an advanced panel data estimation. Tourism Management Perspectives 33, 100611 (2020). https://doi.org/10.1016/j.tmp.2019.100611
4. Castanho, R.A., Couto, G., Pimentel, P., Carvalho, C., Sousa, A.: Territorial management and governance, regional public policies and their relationship with tourism: a case study of the Azores Autonomous Region. Sustainability 12, 6059 (2020). https://doi.org/10.3390/su12156059
5. Ulucak, R., Yücel, A.G., İlkay, S.Ç.: (2020) Dynamics of tourism demand in Turkey: panel data analysis using gravity model. Tour. Econ. 26(8), 1394–1414 (2020). https://doi.org/10.1177/1354816620901956