Andrey N. Plyushchenko Arseny M. Shur On Brzozowski's Conjecture for the Free Burnside Semigroup Satisfying <i>x</i><sup>2</sup> = <i>x</i><sup>3</sup>. 362-373 2011 Developments in Language Theory http://dx.doi.org/10.1007/978-3-642-22321-1_31 conf/dlt/2011 db/conf/dlt/dlt2011.html#PlyushchenkoS11