@article{10_4153_CMB_1990_032_4,
     author = {Comerford, Jonell A. and Lee, Y.},
     title = {Product of {Two} {Commutators} as a {Square} in a {Free} {Group}},
     journal = {Canadian mathematical bulletin},
     pages = {190--196},
     year = {1990},
     volume = {33},
     number = {2},
     doi = {10.4153/CMB-1990-032-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1990-032-4/}
}