“Adjusting Anomalies in International Tourist Arrivals to North Sumatra During the Peak COVID-19 Period (April 2020 to June 2022) to Enhance the Validity of Time Series Modeling”, J. of Research in Math. Trends and Tech., vol. 7, no. 2, pp. 72–77, Sep. 2025, doi: 10.32734/jormtt.v7i2.21718.