Paleocene Wuyun flora in Northeast China: Woodwardia bureiensis, Dryopteris sp. and Osmunda sachalinensis
WANG Qing, Albert G. ABLAEV, WANG Yu-Fei, LI Cheng-Sen
J Syst Evol . 2006, (6): 712 -720 .  DOI: 10.1360/aps040129