Immanuel Kant (2015). “THE THREE CRITIQUES: The Critique of Pure Reason, The Critique of Practical Reason & The Critique of Judgment: The Base Plan for Transcendental Philosophy, The Theory of Moral Reasoning and The Critiques of Aesthetic and Teleological Judgment”, p.936, e-artnow
Justus von Liebig (1855). “Principles of agricultural chemistry with special reference to the late researches made in England: By Justus von Liebig. (Ed. by William Gregory)”, p.31
Horace Greeley (1872). “The Autobiography of Horace Greeley: Or, Recollections of a Busy Life: to which are Added Miscellaneous Essays and Papers”, p.148