Krzysztof Zatwarnicki Guaranteeing Quality of Service in Globally Distributed Web System with Brokers. 374-384 2011 ICCCI (2) http://dx.doi.org/10.1007/978-3-642-23938-0_38 conf/iccci/2011-2 db/conf/iccci/iccci2011-2.html#Zatwarnicki11