@article{article225ac625,
title   = {Poisson brackets and two-generated subalgebras of rings of polynomials},
author = {Shestakov, Ivan P and Umirbaev, Ualbai U},
year = {2004},
doi = {10.1090/S0894-0347-03-00438-7},
journal   = {Journal of the American Mathematical Society}
}