Cioruța, Bogdan-Vasile, Alexandru Leonard Pop, and Mirela Coman. “Implications of Philately in the Representation of the Ceahlau National Park from Romania - An Ecological Revised Case Study”. Asian Journal of Geographical Research 4, no. 2 (May 14, 2021): 31–43. Accessed July 27, 2021. https://journalajgr.com/index.php/AJGR/article/view/57.