Merriam-Webster's Encyclopædia of World Religions. Merriam-Webster. 1999. p. 408. ISBN978-0877790440. Consultado el 31 de octubre de 2011. (requiere registro). «Halloween, also called All Hallows' Eve, holy or hallowed evening observed on October 31, the eve of All Saints' Day. The Irish pre-Christian observances influenced the Christian festival of All Hallows' Eve, celebrated on the same date.»
bbc.co.uk
«BBC – Religions – Christianity: All Hallows' Eve». British Broadcasting Corporation (BBC). 2010. Consultado el 1 de noviembre de 2011. «It is widely believed that many Hallowe'en traditions have evolved from an ancient Celtic festival called Samhain which was Christianised by the early Church».