Simpen, I.N. et al. 2022. Green Nano-Composite of CaO/K-Sulfated TiO2 and Its Potential as a Single-Step Reaction Solid Catalyst for Biofuel Production. KnE Life Sciences. 7, 3 (Jun. 2022), 382–392. DOI:https://doi.org/10.18502/kls.v7i3.11146.