Dwatmadji, Purnomoadi, A., Suteky, T., and Sipriyadi, “Phytogenic feed additives for improving feed efficiency and lowering ruminants’ enteric methane emission on palm oil sludge feed: in vitro study ”, Int. J. Agric. Tech., vol. 22, no. 4, pp. 1687–1702, Jul. 2026.