“Alstonia Scholaris R. Br. And Cassia Siamea Lamk As Possible Biomonitors of Lead and Cadmium in the Polluted Environment of Karachi City, Pakistan”. Journal of Applied Botany and Food Quality, vol. 84, no. 1, Mar. 2012, p. p. 95, https://test.ojs.openagrar.de/index.php/JABFQ/article/view/1703.