Cioruța, B.-V., Coman, M. and Pop, A. L. (2020) “Enhancing and Conservation of Ecosystem through Philatelic Education in Europe: Think Green Concept (IV) - The Second Research Study on First-Day Covers”, Asian Journal of Advanced Research and Reports, 12(1), pp. 22-43. doi: 10.9734/ajarr/2020/v12i130279.