1. Aristóteles (1999) Nicomachean Ethic. Batoche Books, Kitchenner (trans: Ross WD).
http://socserv2.socsci.mcmaster.ca/%7eecon/ugcm/3ll3/aristotle/Ethics.pdf
. Accessed Sept 2012. Also in
http://classics.mit.edu/Aristotle/nicomachaen.html
(Book IV). Accessed Sept 2012
2. Aristotle (1952) Virtues and vices. Aristotle in 23 volumes vol 20 (trans: Rackham H). Harvard University Press, Cambridge. OCLC: 3906945.
http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0062&redirect=true
. Accessed Sept 2012
3. Plato (2001) A República. Lisboa: Edition by Fundação Calouste Gulbenkian. Translated from Greek by J. Burnet, Platonis Opera T. IV, Oxonii e typographeo Clarendoniano, 1949, by Maria Helena da Rocha Pereira
4. Alighieri D (1995) A Divina Comédia. Lisboa: Bertrand Editora, Lda. Translated by Vasco Graça Moura (Original from 1310–14). Also in
http://www.italianstudies.org/comedy/index.htm
(trans: James Finn Cotter). Accessed Sept 2012
5. Cicero (52 BC) De Legibus (On the laws).
http://www.fordham.edu/halsall/ancient/cicero-laws1.asp
. Accessed Sept 2012