Implementation of the Prelle-Singer Method for 1ODEs
  A set of MapleV R5 software routines for solving first order ordinary differential equations (1ODEs) is presented. The package implements the Prelle-Singer Method in its original form plus its extension to include elementary functions (ELFs) on the integrating factor . The package also presents a theoretical extension to deal with all 1ODEs presenting liouvillian solutions (LIS). 
L.G.S. Duarte, S.E.S. Duarte, L.A.C.P. da Mota and J.E.F. Skea (UERJ -   Brazil)