Peirce's Ph.D. student Christine Ladd-Franklin found the truth table in Tractatus Logico-Philosophicus Proposition 5.101, 40 years earlier than Wittgenstein. Christine Ladd (1881), "On the Algebra of Logic", p.62, Studies in Logic, C. S. Peirce ed., 1883
Ragsdale, Samantha. "Christine Ladd-Franklin". Women's Intellectual Contributions to the Study of Mind and Society. 10 Eylül 2015 tarihinde kaynağından arşivlendi. Erişim tarihi: 6 Nisan 2015.
Ragsdale, Samantha. "Christine Ladd-Franklin". Women's Intellectual Contributions to the Study of Mind and Society. 10 Eylül 2015 tarihinde kaynağından arşivlendi. Erişim tarihi: 6 Nisan 2015.