@article{MZ_1977__153_172481,
     author = {Robert G. Burns and Charles C. Edmunds},
     title = {The {Equations} s-1 t-1st=u-1 v-1 uv in a {Free} {Product} of {Groups.}},
     journal = {Mathematische Zeitschrift},
     pages = {83--88},
     publisher = {mathdoc},
     volume = {153},
     year = {1977},
     url = {http://geodesic.mathdoc.fr/item/MZ_1977__153_172481/}
}