On groups of odd order with exactly two non-central conjugacy classes of each size.
The main result of the paper under review is: Let \(G\) be a non-Abelian finite group of odd order and suppose that \(G\) contains exactly two non-central conjugacy classes of the same size. Then \(G\) is isomorphic to the non-Abelian group of order 21.
scientific article; zbMATH DE number 5013989