. . . . . . "2009-12-17" . . . "Robert" . . . . . . . "male" . "1954"^^ . . "Robert Tubbs"@fr . "What is a number? : mathematical concepts and their origins / Robert Tubbs, 2009. - . - LC Authorities. - http://authorities.loc.gov. - 2009-12-17"@fr . "VIAF" . . . "2013-08-08" . . "Robert Tubbs" . . . "2013-08-07"^^ . "Tubbs" . "0000000118449322" . "16166390"^^ . .