SITKI ÇEVRIMLI*, BEKIR, et al. “Effect of O-Cresol, Resorcinol and Hydroquinone on Citric Acid Productivity by Aspergillus Niger in Stirred Fermentor”. Asian Journal of Chemistry, vol. 22, no. 1, Dec. 2009, pp. 699-04, https://asianpubs.org/index.php/ajchem/article/view/16696.