Nurfadillah, A. R., A. Hutuba, and S. M. . Djafar. “Nitrogen Dioxide (NO2) Levels and Health Problems in Street Sellers Around Universitas Negeri Gorontalo (UNG)”. Gema Wiralodra, vol. 14, no. 3, Oct. 2023, pp. 1439-46, doi:10.31943/gw.v14i3.550.