@conference { PL2014c,
author = {  Langevin, Philippe  },
title  = {  New open questions realted to old conjectures by Tor Helleseth },
month  = {  september  },
organization = {  sem. iaa imath },
address = {  Toulon },
year = {2014},
rang = {S},
url  =  {http://langevin.univ-tln.fr/recherche/drafts/openpb.pdf},
}