Effects of polyethylene glycol attachment on physicochemical and biological stability of E-coli L-asparaginase - Soares, Alexandre Learth; Guimarães, Gledson Manso; Polakiewicz, Bronislaw; Pitombo, Ronaldo Nogueira de Moraes; Abrahão Neto, José (International Journal of Pharmaceutics, 2002)