@book{AST_1973__5_,
     author = {Collectif},
     title = {Pseudofunctions and {Helson} {Sets}},
     series = {Ast\'erisque},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {5},
     year = {1973},
     language = {mul},
     url = {http://www.numdam.org/item/AST_1973__5_/}
}