Lukman, Denny, et al. “Postmortem Changes in PH, Color, Drip Loss, and Non-Protein Nitrogen in Beef Liver and Lungs During Storage in Refrigerator”. Acta VETERINARIA Indonesiana, vol. 8, no. 3, Nov. 2020, pp. 56-63, https://doi.org/10.29244/avi.8.3.56-63.