HOLONEC, L., RANGA, F., CRAINIC, D., TRUTA, A. and SOCACIU, C. (2012) “Evaluation of Betulin and Betulinic Acid Content in Birch Bark from Different Forestry Areas of Western Carpathians”, Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 40(2), pp. 99–105. doi: 10.15835/nbha4027967.