Hashmi, Durdana Rais, Ishratullah Siddiqui, Farooq Ahmad Khan, Akhtar Shareef, Ghulam Hussain Shaikh, and Alia Bano Munshi. 2009. “Determination of Copper, Manganese, Nickel and Zinc in Different Cigarette Brands Available in Pakistan: Determination of Metals in Different Cigarettes”. Biological Sciences - PJSIR 52 (6):307-11. https://v2.pjsir.org/index.php/biological-sciences/article/view/573.