Date despre calitatea aerului furnizate de: the Environmental Protection Agency of Jilin Province (吉林省环境保护厅) (sthjt.jl.gov.cn) and the China National Urban air quality real-time publishing platform (全国城市空气质量实时发布平台) (113.108.142.147:20035) and the Weather Underground (wunderground.com) and the Environmental Protection Agency of Jilin Province (吉林省环境保护厅) (hbt.jl.gov.cn)