Maurice Courbage Brunon Kaminski On Lyapunov Exponents for Cellular Automata. 159-168 2009 4 J. Cell. Autom. 2 http://www.oldcitypublishing.com/journals/jca-home/jca-issue-contents/jca-volume-4-number-2-2009/jca-4-2-p-159-168/ db/journals/jca/jca4.html#CourbageK09