J. B. Lightfoot, The Apostolic Fathers, 4 vols. (London: Macmillan Company, 1885) 11, part I:88. Some scholars rightly label Easter-Sunday as “Roman Easter,” see Mosna, Storia della domenica 117, 119, 333; also Mario Righetti, L’Anno liturgico, manuale di storia liturgica, 4 vols. (Milan: Ancora 1969) 11:245–246.