Aziz, Muhammad Abbas, Hamaad Raza Ahmad, Dennis L. Corwin, Muhammad Sabir, Khalid Rehman Hakeem, and Münir Öztürk. 2017. “Influence of Farmyard Manure on Retention and Availability of Nickel, Zinc and Lead in Metal-Contaminated Calcareous Loam Soils”. Journal of Environmental Engineering and Landscape Management 25 (3):289-96. https://doi.org/10.3846/16486897.2016.1254639.