The Environmental Impacts of Informal Economies in China: Inverted U-shaped Relationship and Regional Variances
YANG Jiangmin, TAN Yiming, XUE Desheng, HUANG Gengzhi, XING Zuge
Chinese Geographical Science . 2021, (4): 585 -599 .  DOI: 10.1007/s11769-021-1210-z