His initial contribution to this field was his doctoral thesis in 1962, published in book form in 1964; he later published several of the standard works on the subject. His theoretical work on hierarchical routing, done in the late 1970s with his then-student Farouk Kamoun, is now critical to the operation of today's world-wide Internet. Peki, �

In a US study in 2005, the percentage of men using the Internet was very slightly ahead of the percentage of women, although this difference reversed in those under 30. Men logged on more often, spent more time online, and were more likely to be broadband users, whereas women tended to make more use of opportunities to communicate (such birli email