Machado, C. J. dos S., Nunes, M. L. S. and Vasconcelos, L. M. (2018) “Lessons from a friend: Drummond letters to Zila Mamede”, Revista HISTEDBR On-line. Campinas, SP, 18(1), pp. 107–122. doi: 10.20396/rho.v18i1.8651679.