Navarrete, Ian A., Salfe O. Macalde, and Victor B. Asio. 2009. “Nutrient Characteristics of Aggregates and Rhizosphere of a Degraded Upland Soil: Implication for Soil Fertility Evaluation”. Annals of Tropical Research 31 (1):90-101. https://doi.org/10.32945/atr3115.2009.