@article{10_4171_ggd_348,
     author = {Igor Lysenok and Alexei Miasnikov and Alexander Ushakov},
     title = {Quadratic equations in the {Grigorchuk} group},
     journal = {Groups, geometry, and dynamics},
     pages = {201--239},
     year = {2016},
     volume = {10},
     number = {1},
     doi = {10.4171/ggd/348},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/348/}
}