Charles Sanders Peirce, Nathan Houser, Christian J.W. J. W. Kloesel (1992). “The Essential Peirce, Volume 1: Selected Philosophical Writings? (1867–1893)”, p.114, Indiana University Press
Charles Sanders Peirce, Nathan Houser, Christian J.W. J. W. Kloesel (1992). “The Essential Peirce, Volume 1: Selected Philosophical Writings? (1867–1893)”, p.129, Indiana University Press
Charles Sanders Peirce, Nathan Houser, Christian J.W. J. W. Kloesel (1992). “The Essential Peirce, Volume 1: Selected Philosophical Writings? (1867–1893)”, p.138, Indiana University Press