Borrell, J.G. and Silva, I.A. 2000. Gastric probe used in pré-term newborn: study of the alteration in flexibility of constituent polymer. Revista da Escola de Enfermagem da USP. 34, 3 (Sep. 2000), 302–308. DOI:https://doi.org/10.1590/S0080-62342000000300012.