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 https://free-blog.org/internet-ve-telekomunikasyonda-guvenilir-cozum-plusnet/