Yusta, G. Maria, et al. “Quality of Yeast Extract of Industry Yeast Press Alcohol Waste As Drying Result With Various Temperature Variation”. Journal of Natural Sciences and Mathematics Research, vol. 2, no. 2, Aug. 2017, pp. 176-80, https://journal.walisongo.ac.id/index.php/JNSMR/article/view/1664.