Handayani, P.A. et al. 2019. Response Surface Optimization of Biodiesel Production from Nyamplung (Calophyllum inophyllum) Oil Enhanced by Microwave and Ionic liquid + NaOH Catalyst. Periodica Polytechnica Chemical Engineering. 63, 3 (Jan. 2019), 406–413. https://doi.org/10.3311/PPch.12965.