S. Lodoysamba, D. Shagjjamba and G. Gerelmaa 2022. Characterization of PM2.5 and PM10-2.5 air pollution of Ulaanbaatar city. Scientific transaction of the National University of Mongolia. Physics. 15, 309 (Mar. 2022), 1–4. DOI:https://doi.org/10.22353/physics.v15i309.251.