Saurabh Srivastava Phalguni Gupta Approximating the Range Sum of a Graph on CREW PRAM. 312-318 2002 conf/iwdc/2002 IWDC http://link.springer.de/link/service/series/0558/bibs/2571/25710312.htm db/conf/iwdc/iwdc2002.html#SrivastavaG02