HUSAIN, T. and GARG, A. 2006. Lectotypification of Pedicularis roylei var. speciosa (Scrophulariaceae) and differentiation from the type variety. Edinburgh Journal of Botany. 62, 1-2 (Feb. 2006), 93–94. DOI:https://doi.org/10.1017/S0960428606210059.