[1960_1] Enriques, Federigo, Introduction, in R. Bonola, Non-Euclidean Geometry; a critical and historical study of its development, Dover Publ., New York, 1960, pp. V-VI. authorized Engl. translation by H.S. Carslaw, with an Introd. by Federigo Enriques. Ristampa di [1912_8]. Ristampa di [1955_1]. | MathSciNet