The Gerasimov-Drell-Hearn Sum Rule and Current Algebras
  The status of the Gerasimov-Drell-Hearn sum rules for polarized inclusive photo-production on nucleons is reviewed. It is shown that results from currently available data compare favorably with an estimate based on an extended current algebra. Implications for integrals of spin-dependent structure functions are also briefly discussed. 
Lay Nam Chang, Yigao Liang, and Ron L. Workman