2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48597The history and present status of several sum rules for deep-inelastic lepton scattering are reviewed, with particular attention to the discovery of scaling, partons, quarks and QCD. Two outstanding issues are then discussed in more detail: the singlet (Ellis-Jaffe) nucleon spin sum rule and the Drell-Hearn-Gerasimov-Iddings sum rule.Talk given at the Sid Drell Symposium, SLAC, Stanford, California, July 31st, 1998, 17 pages LaTeX, 2 figures, uses cernart.cls (included)High Energy Physics - Phenomenologytext