@article{10_1017_S0017089500000410,
     author = {McCool, James},
     title = {Elements of finite order in free product sixth-groups},
     journal = {Glasgow mathematical journal},
     pages = {128--145},
     year = {1968},
     volume = {9},
     number = {2},
     doi = {10.1017/S0017089500000410},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500000410/}
}