Isam Eldin Hussein Elgailani and Christina Yacoub Ishak, Trans., “Methods for Extraction and Characterization of Tannins from Some Acacia Species of Sudan”, Pak. J. Anal. Environ. Chem., vol. 17, no. 1, pp. 43 – 49, Jan. 2016, doi: 10.21743/pjaec/2016.06.007.