Okareh, O. T., O. D. Enesi, and R. Olawoyin. “Production of Citric Acid from Solid State Fermentation of Sugarcane Waste Using <i>Aspergillus Niger</i> And Indigenous Sugarcane Microflora”. African Journal of Sustainable Development, vol. 6, no. 1, Mar. 2016, pp. 147-60, https://www.ajol.info/index.php/ajsd/article/view/131665.