“Vehicular Traffic Air Pollution As Expressed by Leaves of Senna Occidentalis (L.) Link from Three Busy Roads in Nigeria”. Biological Sciences - PJSIR, vol. 60, no. 3, Dec. 2017, pp. 162-7, https://doi.org/10.52763/PJSIR.BIOL.SCI.60.3.2017.162.167.