1. R. C. Buck and E. F. Buck, Advanced calculus, 3rd ed., McGraw-Hill, New York, etc., 1978.
2. Calculus with Analytic Geometry. By George F. Simmons
3. [G. de L'Hôpital], Analyse des infiniment petita. pour l'intelligence des lignes courbes, Paris, 1696; later editions under the name of le Marquis de L'Hôpital.