Salman, S., K. Sinaga, M. Indriana, and S. Maharani. “THE EFFECT OF COFFEE LEATHER FERMENTATION BY Aspergillus Niger WITH THE ADDITION OF TWO VARIATIONS OF THE CONCENTRATION OF UREA AND AMMONIUM SULPHATE USING TWO FERMENTATION TECHNIQUES ON CRUDE FIBER”. Journal of Pharmaceutical And Sciences, Vol. 5, no. 2, July 2022, pp. 156-69, doi:10.36490/