Leibniz, Gottfried Wilhelm. The Early Mathematical Manuscripts of Leibniz. Cosimo, Inc., 2008. Page 228. Copy
doi.org
dx.doi.org
Katz, Mikhail; Sherry, David (2012), «Leibniz’s Infinitesimals: Their Fictionality, Their Modern Implementations, and Their Foes from Berkeley to Russell and Beyond», Erkenntnis, doi:10.1007/s10670-012-9370-y.