Measurements of electron drift velocity in isobutane using the pulsed townsend technique - Vivaldini, Túlio C; Lima, Iara B; Gonçalves, Josemary A C; Botelho, Suzana; Tobias, Carmen C B; Ridenti, Marco A; Pascholati, Paulo Reginaldo; Fonte, Paulo; Mangiarotti, Alessio (SBF, 2010)