Cioruța, B.-V., A. L. Pop, and M. Coman. “Implications of Philately in the Representation of the Ceahlau National Park from Romania - An Ecological Revised Case Study”. Asian Journal of Geographical Research, vol. 4, no. 2, May 2021, pp. 31-43, doi:10.9734/ajgr/2021/v4i230129.