Naji Rad, Sumayyah, Ghavidel, Akbar, Alikhani, Hossein Ali, Ashraf Soltnai Toolarood, Ali. “The Investigation of Heavy Metal Content and Their Chemical Forms in Tehran Sewage Sludge for Agricultural Application.” Journal of Environmental Science and Technology, vol. 20, no. 1, 2018, pp. 1-13. 10.22034/jest.2018.12454