Pusoh, G., Kalangi, L. and Pangerapan, S. 2026. Does the opsen scheme reduce provincial tax effectiveness? Motor vehicle tax and title transfer fee in North Sulawesi Province. The Contrarian : Finance, Accounting, and Business Research. 5, 2 (Oct. 2026), 391–400. DOI:https://doi.org/10.58784/cfabr.521.