Gilbert Held Measure Web traffic with caution. 181-182 1997 7 Int. J. Netw. Manag. 4 https://doi.org/10.1002/(SICI)1099-1190(199707/08)7:4<181::AID-NEM263>3.0.CO;2-1 db/journals/ijnm/ijnm7.html#Held97d