Lumbantoruan, M. R., Panjaitan, H. P., & Chandra, T. (2021). THE INFLUENCE OF COVID-19 EVENTS TO VACCINATION ON ABNORMAL RETURN AND TRADING VOLUME ACTIVITY IN IDX30 COMPANIES. Journal of Applied Business and Technology, 2(3), 183-193. https://doi.org/10.35145/jabt.v2i3.75