Florence Nightingale, Lynn McDonald (2004). “Florence Nightingale on Public Health Care: Collected Works of Florence Nightingale”, p.122, Wilfrid Laurier Univ. Press
Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.53, Skyhorse Publishing, Inc.
Florence Nightingale, Lynn McDonald (2004). “Florence Nightingale on Public Health Care: Collected Works of Florence Nightingale”, p.291, Wilfrid Laurier Univ. Press