Jassim, E. H. . and Ameen, S. K. M. . (2014) “Influence of L-Tryptophan and salicylic acid on secondary metabolites production from leaves induced callus of Catharanthus roseus L.G.Don in vitro”, Journal of Biotechnology Research Center (JOBRC), 8(2), pp. 35–43. doi: 10.24126/jobrc.2014.8.2.326.