“THE EFFECT OF COMBINATION VEGETABLE TANNING MATERIALS AND SULPHITED OIL ON THE PHYSICAL PROPERTIES OF JACKET LEATHER ”. Berkala Penelitian Teknologi Kulit, Sepatu, Dan Produk Kulit , vol. 21, no. 2, Dec. 2024, pp. 297-0, https://doi.org/10.58533/rhvpj273.