The historical process of the masonry city walls construction in China during 1st to 17th centuries AD Xue, Qiaofeng ; Jin, Xiaobin ; Cheng, Yinong ; Yang, Xuhong ; Jia, Xin ; Zhou, Yinkang Abstract Publication: PLoS ONE Pub Date: March 2019 DOI: 10.1371/journal.pone.0214119 Bibcode: 2019PLoSO..1414119X