Beate Bollig Stephan Waack Philipp Woelfel Parity graph-driven read-once branching programs and an exponential lower bound for integer multiplication. 86-99 2006 362 Theor. Comput. Sci. 1-3 http://dx.doi.org/10.1016/j.tcs.2006.05.035 db/journals/tcs/tcs362.html#BolligWW06