https://arxiv.org/abs/0801.4614
[0801.4614] Nonisomorphic curves that become isomorphic over extensions of coprime degrees
Abstract page for arXiv paper 0801.4614: Nonisomorphic curves that become isomorphic over extensions of coprime degrees
https://kconrad.math.uconn.edu/nonisomgp.html
Counting nonisomorphic groups
countinggroups