Volatile fatty acids concentration and efficiency of microbial protein synthesis of concentrate cassava peel diet with different levels of protein sourcesArya Dwi Saputra, Kusmartono Kusmartono, Mashudi Mashudi and Poespitasari Hazanah NdaruE3S Web Conf., 335 (2022) 00029DOI: https://doi.org/10.1051/e3sconf/202233500029