Rahmawati, Sri, et al. “Review Journal: The Effect of Heterogeneous Zeolite Catalyst and Modified Zeolite Catalysts on Biogaseline Yields”. International Journal of Sustainable English Language, Education, and Science, vol. 1, no. 2, Dec. 2024, pp. 49-56, https://doi.org/10.71131/1tqsre11.