David Ricardo, John Ramsay McCulloch (1852). “The Works of David Ricardo. With a notice of the life and writings of the author: by J. R. McCulloch”, p.68
Robert Owen (1841). “A development of the principles and plans on which to establish self-supporting home colonies: as a most secure and profitable investment for capital, and an effectual means permanently to remove the causes of ignorance, poverty, and crime”, p.7
Lysander Spooner (1886). “A Letter to Grover Cleveland on His False Inaugural Address, the Usurpation and Crimes of Lawmakers and Judges, and Consequent Poverty, Ignorance, and Servitude of the People”
Gary Becker, Guity Becker, Guity Nashat (1998). “The Economics of Life: From Baseball to Affirmative Action to Immigration, How Real-World Issues Affect Our Everyday Life”, McGraw Hill Professional