1. Avec Marius van der Put: A local-global problem for linear differential equations. To appear in the Pacific Journal of Mathematics.

2. A note about rational representations of differential Galois groups.
 PostScript ,  PDF

3. Avec Marius van der Put, Galois theory of q-difference equations, 2006, 55 p. (to appear in "Annales de la Faculté des Sciences de Toulouse").
 PostScript ,  PDF

4. Avec Marius van der Put: Krichever modules for difference and differential equations, Astérisque 296, 2004, p.207-225.

5. (2003) Towards a geometric correspondence for $\sigma $-difference derivations.
 PostScript ,  DVI

6. (1999) Harmonic cocycles and cohomology of arithmetic groups (in positive characteristic).
PostScript(TM) file (1718 Ko), DVI file (124 Ko)

7. On modular Forms of characteristic p>0, Journal of Number Theory 84, p. 214-229, 2000.

8. Avec Marius van der Put: Drinfeld's Reciprocity Law, in Drinfeld Modules, Modular Schemes and Applications, proceedings of the workshop at Alden Biesen (E.-U;Gekeler, M.van der Put, M.Reversat and J.Van Geel eds), World Scientific, 1997.