@article{10_1017_S0017089500009150,
     author = {Humphries, Stephen P.},
     title = {Some subgroups of {SL(3,} z) generated by involutions},
     journal = {Glasgow mathematical journal},
     pages = {127--136},
     year = {1990},
     volume = {32},
     number = {2},
     doi = {10.1017/S0017089500009150},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500009150/}
}