Disorder effects on the charge-density waves structure in V- and W-doped blue bronzes : Friedel oscillations and charge-density wave pinning 10 janvier 2006 Ravy, S., Rouzière, S., Pouget, J.-P., Brazovskii, S., Marcus, J., Bérar, J.-F., Elkaim, E. Physical Review B 74 (2006) 174102