Christophe Hohlweg Christophe Reutenauer Lyndon words, permutations and trees. 173-178 2003 307 Theor. Comput. Sci. 1 http://dx.doi.org/10.1016/S0304-3975(03)00099-9 db/journals/tcs/tcs307.html#HohlwegR03