Constancy checks of HDR well-type ionization chambers in the linac era: potential use of a 90Sr source - Borguezan Neto, Euclydes; Lima, Fabrício Augusto de; Branco, Isabela Soares Lopes; Barbi, Gustavo Lázzaro; Bruno, Alexandre Colello; Arruda, Gustavo Viani; Pavoni, Juliana Fernandes (Applied Radiation and Isotopes, 2020)