https://twitter.com/Treyarch/status/332582728186859521 http://mp1st.com/2013/05/09/black-ops-2-double-xp-weekend-kicks-off-tomorrow-may-10/ http://www.teamplayers.es/2013/05/09/fin-de-semana-de-doble-xp-en-black-ops-2-para-todas-las-plataformas/
