@article{GDZPPN002345889,
title = {Some Unsolvable Problems about Elements and Subgroups of Groups.},
journal = {Mathematica Scandinavica},
volume = {7},
year = {1959},
pages = {191-201},
zbl = {0104.00704},
url = {http://dml.mathdoc.fr/item/GDZPPN002345889}
}
Neumann, B.H.; Baumslag, G.; Boone, W.W. Some Unsolvable Problems about Elements and Subgroups of Groups.. Mathematica Scandinavica, Tome 7 (1959) pp. 191-201. http://gdmltest.u-ga.fr/item/GDZPPN002345889/