Analytic and semi-analytic solution of the coupled DGLAP equations at   small x by the method of characteristics
  In this paper we present solutions of the coupled DGLAP equations for quark and gluon singlet by applying the method of characteristics. Solutions are presented both in analytic and semi-analytic forms, compared with the exact results and the validity range obtained. 
D. K. Choudhury and P. K. Sahariah