Tilly Mándy, A., P. Honfi, É. Stefanovits-Bányai, I. D. Mosonyi, V. Köbli, and K. Hrotkó. 2010. “The Effect of 5-Aminolevulinic-Acid (ALA) on the Development of Saintpaulia Ionantha”. International Journal of Horticultural Science 16 (5): 33-36. https://doi.org/10.31421/IJHS/16/5/931.