Kazuhiko Kusano Wataru Matsubara Akira Ishino Hideo Bannai Ayumi Shinohara New Lower Bounds for the Maximum Number of Runs in a String http://arxiv.org/abs/0804.1214 2008 CoRR abs/0804.1214 db/journals/corr/corr0804.html#abs-0804-1214 informal publication