Lelesz, J. Éva and József Csajbók 2019. The changes of the purple coneflower’s (Echinacea purpurea L.) herb and radix drug yield under different fertilization conditions. Acta Agraria Debreceniensis. 1 (May 2019), 79–83. DOI:https://doi.org/10.34101/actaagrar/1/2375.