On some $\cal D$-modules in dimension 2
  We prove a duality formula for two ${\cal D}$-modules arising from logarithmic derivations w.r.t. a plane curve. As an application we give a differential proof of a logarithmic comparison theorem of Calder\'on-Mond-Narv\'aez-Castro. 
F.J. Castro-Jim\'enez and J.M. Ucha-Enriquez