Nurfadillah, A. R., Hutuba, A., & Djafar, S. M. . (2023). Nitrogen dioxide (NO2) levels and health problems in street sellers around Universitas Negeri Gorontalo (UNG). Gema Wiralodra, 14(3), 1439–1446. https://doi.org/10.31943/gw.v14i3.550