University of Isfahan International Journal of Group Theory 2251-7650 7 1 2018 03 01 Countably recognizable classes of groups with restricted conjugacy classes 5 16 21235 10.22108/ijgt.2016.21235 EN Francesco De Giovanni Dipartimento di Matematica e Applicazioni - University of Napoli "Federico II" Marco Trombetti Universita di Napoli Federico II, Journal Article 2016 04 30 A group class ${ X}$ is said to be countably recognizable if a group belongs to ${X}$ whenever all its countable subgroups lie in ${X}$‎. ‎It is proved here that most of the relevant classes of groups defined by restrictions on the conjugacy classes are countably recognizable‎. ‎conjugacy class‎ ‎countable recognizability https://ijgt.ui.ac.ir/article_21235_894f1a96aa9ff81f3b1db138105bf512.pdf