Mir Munsif Ali Talpur, Tajnees Pirzada, Waheed Ali, Mohammad Hussain Arain, Samina Rajper, and Mazar Khaskheli , Trans., “Isolation and Characterization of Soil Fulvic Acid”, Pak. J. Anal. Environ. Chem., vol. 17, no. 1, pp. 8 – 17, Jan. 2016, doi: 10.21743/pjaec/2016.06.002.