@article{10_4153_CJM_1970_094_6,
     author = {McCool, James},
     title = {Unsolvable {Problems} in {Groups} {With} {Solvable} {Word} {Problem}},
     journal = {Canadian journal of mathematics},
     pages = {836--838},
     year = {1970},
     volume = {22},
     number = {4},
     doi = {10.4153/CJM-1970-094-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1970-094-6/}
}