Ali Aberkane James D. Currie There Exist Binary Circular 5/2<sup>+</sup>; Power Free Words of Every Length. 2004 11 Electr. J. Comb. 1 http://www.combinatorics.org/Volume_11/Abstracts/v11i1r10.html db/journals/combinatorics/combinatorics11.html#AberkaneC04