Remove warnings

bibliography.bib

@@ -64,7 +64,7 @@
 }
 
 @ONLINE{bib:code-aster:contact,
-  url    = {http://www.code-aster.org/V2/doc/default/en/man_r/r5/r5.03.50.pdf},
+  url    = {http://www.code-aster.org/V2/doc/default/en/man\_r/r5/r5.03.50.pdf},
   title  = {{[R5.03.50]} Discrete formulation of the contact-friction},
   author = {Mickael ABBAS},
   year   = {2012}
@@ -79,14 +79,15 @@ simulations},
 }
 
 @ONLINE{bib:salome:geom,
-  url    = {http://docs.salome-platform.org/salome_6_5_0/gui/GEOM/index.html},
+  url    = 
+{http://docs.salome-platform.org/salome\_6\_5\_0/gui/GEOM/index.html},
   title  = {SALOME Geometry User's Guide},
   year   = {2012}
 }
 
 @ONLINE{bib:salome:additional_geom,
   url    =
-{http://docs.salome-platform.org/salome_6_5_0/gui/GEOM/SALOME_BOA_PA.pdf},
+{http://docs.salome-platform.org/salome\_6\_5\_0/gui/GEOM/SALOME\_BOA\_PA.pdf},
   title  = {General Fuse Algorithm, Partition Algorithm, Boolean Operations
 Algorithm. Backgrounds.},
   year   = {2010} 
@@ -101,7 +102,7 @@ Algorithm. Backgrounds.},
 }
 
 @ONLINE{bib:code-aster:common,
-  url = {http://www.code-aster.org/V2/UPLOAD/DOC/Presentation/2007_nafems.pdf},
+  url = {http://www.code-aster.org/V2/UPLOAD/DOC/Presentation/2007\_nafems.pdf},
   title    = {Free Software for Computational Mechanics: EDF’s Choice},
   author   = {Christophe Durand},
   year     = {2007}
@@ -109,7 +110,7 @@ Algorithm. Backgrounds.},
 
 @ONLINE{bib:code-aster:presentation,
   url    =
-{http://www.code-aster.org/V2/UPLOAD/DOC/Presentation/2008_Manchester.pdf},
+{http://www.code-aster.org/V2/UPLOAD/DOC/Presentation/2008\_Manchester.pdf},
   title  = {Analyse des Structures et Thermo-m\'{e}canique pour des \'{E}tudes
 et des Recherches},
   year   = {2007}