“PHYSICAL AND CHEMICAL CHARACTERISTICS OF BOVINE HIDE GELATIN WITH THE TYPE AND CONCENTRATION OF ACID AS A PRE -TREATMENT SOLUTION”. Berkala Penelitian Teknologi Kulit, Sepatu, Dan Produk Kulit , vol. 22, no. 1, Dec. 2024, pp. 23-32, https://doi.org/10.58533/2dk4e462.