D.  Kim, Lee, S., Abraham, A., and Han, S., ?A dynamic priority allocation scheme of messages for differentiated web services satisfying service level agreement?, Journal of Digital Information Management, vol. 4, no. 1, pp. 26 - 31, 2006.

M. C.  Jaeger and Ladner, H., ?A model for the aggregation of QoS in WS compositions involving redundant services?, Journal of Digital Information Management, vol. 4, no. 1, pp. 44 - 49, 2006.