Spatial and PMF analysis of particle size distributions simultaneously measured at four locations at the roadside of highways - Nam Geon Kim; Sang Bin Jeong; Hyoun Cher Jin; Jiwon Lee; Kyung Hwan Kim; San Kim; Yongmi Park; Wonsik Choi; Kyung-Hwan Kwak; Hyunho Lee; Giwon Kang; Changhyuk Kim; et al. (Science of The Total Environment, 2023)