@article{JEMS_2008_10_2_a10,
     author = {Leonid Makar-Limanov and Jie-Tai Yu},
     title = {Degree estimate for subalgebras generated by two elements},
     journal = {Journal of the European Mathematical Society},
     pages = {533--541},
     publisher = {mathdoc},
     volume = {10},
     number = {2},
     year = {2008},
     doi = {10.4171/jems/121},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/121/}
}