Florence Nightingale, Michael D. Calabria, Janet A. Macrae (1994). “Suggestions for Thought by Florence Nightingale: Selections and Commentaries”, p.114, University of Pennsylvania Press
John Tillotson (1696). “The Works of the Most Reverend Dr. John Tillotson ...: Containing Fifty Four Sermons and Discourses, on Several Occasions. Together with The Rule of Faith”, p.663