Understanding the influences of different pretreatments on recalcitrance of Populus natural variants Authors Yao, Lan; Yang, Haitao; Yoo, Chang Geun; Pu, Yunqiao; Meng, Xianzhi; Muchero, Wellington; Tuskan, Gerald A.; Tschaplinski, Timothy J.; and Ragauskas, Arthur J. Journal-Book Bioresource Technology Year 2018