Thorstein Veblen (2016). “THE THEORY OF THE LEISURE CLASS: An Economic Study of American Institutions and a Social Critique of Conspicuous Consumption: Development of Institutions That Shape Society and Influence the Livelihood of Citizens: Based on Sociological & Economical Theories of Charles Darwin, Karl Marx, Adam Smith and Herbert Spencer”, p.7, e-artnow
Theodore Roosevelt (2012). “Compilation of the Messages and Papers of the Presidents Section 2 (of 2) of Supplemental Volume: Theodore Roosevelt, Supplement”, p.23, tredition