Akhar, F.K. and Bagheri, A. 2013. The Effect of Hormonal Composition, Type of Explant and Light Condition on Callus Production in Periwinkle (Catharanthus roseus L.). Plant Tissue Culture and Biotechnology. 23, 1 (Jul. 2013), 107?113. DOI:https://doi.org/10.3329/ptcb.v23i1.15567.