RT Journal T1 On torsion free class and cover class in category of comodules A1 LI Yuan, YAO Hai-lou PB JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) FD YR 2020 JF JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) JO JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) VO 55 IS 8 SP 1 DO 10.6040/j.issn.1671-9352.0.2019.869 K1 cover class;maximal tilting;torsion free class;cover comodule LK {http://lxbwk.njournal.sdu.edu.cn/EN/article/article_3309.shtml}