Plantilla:MacTutor
O'Connor, John J.; Robertson, Edmund F. «MacTutor» (en anglès). MacTutor History of Mathematics archive. School of Mathematics and Statistics, University of St Andrews, Scotland.
O'Connor, John J.; Robertson, Edmund F. «MacTutor» (en anglès). MacTutor History of Mathematics archive. School of Mathematics and Statistics, University of St Andrews, Scotland.