Shunsuke Inenaga Hideo Bannai Heikki Hyyrö Ayumi Shinohara Masayuki Takeda Kenta Nakai Satoru Miyano Finding Optimal Pairs of Cooperative and Competing Patterns with Bounded Distance. 32-46 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3245&spage=32 2004 conf/dis/2004 Discovery Science db/conf/dis/dis2004.html#InenagaBHSTNM04