1. Aquinas, T. (2018a) S. th. II, 2, 40, http://www.newadvent.org/summa/3040.htm.. Accessed 15 June 2018.
2. Aquinas, T., (2018b) S. th. II, 2, 64, from: http://www.newadvent.org/summa/3064.htm. Accessed 15 June 2018.
3. Carion, C. (2004). Joyeux Noël. USA: Sony Pictures Classics.
4. Crocker, T. B. (2015). The Christmas truce: Myth, memory, and the first world war. USA: The University Press of Kentucky.
5. Fiala, A. (2010) Pacifism, Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/pacifism/. Accessed 26 Jan 2012.