Santoso, A., L. Ramadhan, B. Susilo, S. Sukarni, A. Wijaya, S. Sumari, M. Muntholib, I. N. Pramesti, and M. R. Asrori. “Conversion of Waste Cooking Oil With Transesterification Process in Ultrasonicator Using SrO-KF Catalyst”. Orbital: The Electronic Journal of Chemistry, Vol. 16, no. 3, Sept. 2024, pp. 136-42, doi:10.17807/orbital.v16i3.18661.