Beijing in 2016 saw more 'good air' days - China - Chinadaily.com.cn
Browner, but greener
Maps show drastic drop in China's air pollution after coronavirus quarantine - The Verge
China Declared a War on Pollution and Four Years Later It's Winning | EPIC
Evidence of air quality data misreporting in China: An impulse indicator saturation model comparison of local government-reported and U.S. embassy-reported PM2.5 concentrations (2015–2017) | PLOS ONE