Brown, Bryson. 2004. Knowledge and non-contradiction. In The Law of Non-Contradiction: New Philosophical Essays, edited by G. Priest, Jc. Beall and B. Armour-Garb. Oxford: Clarendon Press.10.1093/acprof:oso/9780199265176.003.0009
Frege, Gottlob. 1879-1891. Logic. In Posthumous Writings, translated by P. Long and R. White, edited by H. Hermes, F. Kambartel and F. Kaulbach. Oxford: Blackwell, 1979.
Frege, Gottlob. 1919. Negation. In Translations from the Philosophical Writings of Gottlob Frege, edited by P. Geach and M. Black. Oxford: University College London Press, 1960.
Frege, Gottlob. 1980. Philosophical and Mathematical Correspondence. Translated by H. Kaal, edited by G. Gabriel, H. Hermes, F. Kambartel, C. Thiel and A. Veraart. Oxford: Blackwell.
MacFarlane, John. 2011. What is assertion? In Assertion: New Philosophical Essays, edited by J. Brown and H. Cappelen. Oxford: Oxford University Press.10.1093/acprof:oso/9780199573004.003.0004