@article{article6e809baa,
title   = {Group identities on symmetric units},
author = {Giambruno, Antonio and Polcino Milies, Francisco César and Sehgal, Sudarshan K.},
year = {2009},
doi = {10.1016/j.jalgebra.2009.06.025},
journal   = {Journal of Algebra}
}