1. Alpman, S. A., Balestra, C., & Murtin, F. (2018). Unveiling the monetary value of non-market activities using experienced well-being and time-use. Paper prepared for the 35th IARIW General Conference. Retrieved Jul 1, 2020, from http://www.iariw.org/copenhagen/alpman.pdf.
2. Álvarez-Farizo, B., Hanley, N., & Barberán, R. (2001). The value of leisure time: a contingent rating approach. Journal of Environmental Planning and Management, 44(5), 681–699. https://doi.org/10.1080/09640560120079975.
3. Balkiz, O. (2016). Assessment of the socio-economic values of goods and services provided by Mediterranean forest ecosystems—Düzlerçami Forest, Turkey. Valbonne: Orman Genel Müdürlüğü, Doğa Koruma Merkezi and Plan Bleu. Retrieved Jul 2, 2020, from http://www.fao.org/3/a-i6131e.pdf.
4. Bartczak, A. (2011). Metoda kosztu podróży (TCM). In M. Czajkowski, A. Kopańska, A. Markowska, T. Żylicz, K. Rykowski, M. Zandersen, & M. Termansen (Eds.), Wartości nierynkowych korzyści z lasów. Metody wyceny oraz zastosowanie wyników w analizach ekonomicznych (pp. 12–27). Warszawa: Polforex.
5. Baveye, P. C., Baveye, J., & Gowdy, J. (2016). Soil “Ecosystem” services and natural capital: critical appraisal of research on uncertain ground. Frontiers in Environmental Science, 4, 41. https://doi.org/10.3389/fenvs.2016.00041.