Second-birth Intentions and Mental Health among Women Aged at Least 30 in Their Second Pregnancies during the Implementation of the Universal Two-child Policy in China:a Survey in Small- and Medium-sized Cities of Anhui Province 
LU Xuelei,JIANG Chunxiao,WANG Ling,WU Huabing,NIU Qingshan,ZHANG Chi,ZHONG Qi,HUANG Fen
Chinese General Practice . 2020, (11): 1406 -1410 .  DOI: 10.12114/j.issn.1007-9572.2019.00.512