Kazuo Iwama Yasuo Okabe Toshiro Takase Separating Oblivious and Non-oblivious BPs. 28-38 2001 conf/cocoon/2001 COCOON http://link.springer.de/link/service/series/0558/bibs/2108/21080028.htm db/conf/cocoon/cocoon2001.html#IwamaOT01