Sardón Nina, Sandro, Raúl D. Zapata Hernández, and Luis A. Arias López. 2021. “Comparison of Organic Carbon from Humic and Fulvic Acids and the Degree of Humification in Five Soil Orders”. Peruvian Journal of Agronomy 5 (1): 25-34. https://doi.org/10.21704/pja.v5i1.1676.