Fragmentation pattern of amides by EI and HRESI: study of protonation sites using DFT-3LYP data - Fokoue, Harold Hilarion; Marques, J. V; Correia, M. V; Yamaguchi, L F; Qu, X; Sousa, J. Aires de; Scotti, M T; Lopes, Norberto Peporine; Kato, Massuo Jorge (RSC Advances, 2018)