On the finiteness of Pythagoras numbers of real meromorphic functions

Acquistapace, Francesca; Broglia, Fabrizio; Fernando, José F.; Ruiz, Jesús M.

Bulletin de la Société Mathématique de France, Volume 138 (2010) p. 231-247

On the pythagoras numbers of real analytic surfaces

Acquistapace, Francesca; Broglia, Fabrizio; Fernando, José F.; Ruiz, Jesús M.

Annales scientifiques de l'École Normale Supérieure, Volume 38 (2005) p. 751-772