Berlioz, D. (1995). The "Co-existent" and "In-existent" Calculus and Leibnizian Metaphysics of Expression. Acta Universitatis Lodziensis. Folia Philosophica. Ethica-Aesthetica-Practica, (11), 111–124. https://doi.org/10.18778/0208-6107.11.08