Calculus Ratiocinator vs. Characteristica Universalis? The Two Traditions in Logic, Revisted (Wiederabdruck)
V. Peckhaus, in: M. Beaney, E.H. Reck (Eds.), Gottlob Frege. Critical Assessments of Leading Philosophers, Bd. 1: Frege’s Philosophy in Context, Routledge, London/ New York, 2005, pp. 176–190.