Алтанхуяг М, Дамдинсүрэн Б, Дагва Ш. Source Apportionment of Air Particulate Matter in Ulaanbaatar City (2017–2019) Using Positive Matrix Factorization. Sci. tran. NUM, Phys. [Internet]. 2025 Jun. 29 [cited 2026 Jan. 9];38(621):40-8. Available from: https://journal.num.edu.mn/physics/article/view/10086