Earliest systematic coal exploitation for fuel extended to ~3600 B.P. - Menghan Qiu; Ruiliang Liu; Xingyuan Li; Linyao Du; Qiurong Ruan; Pollard, A. Mark; Shanjia Zhang; Xiao Yuan; Fengwen Liu; Gang Li; Gaojun Li; Zhimin Jiao; et al. (Science Advances, 2023)