Bonola, R., Carslaw, H. S., Enriques, F., Bolyai, J., & Lobachevski, N. (1955). Non-Euclidean geometry: A critical and historical study of its development ; authorized English translation with additional appendices by H. S. Carslaw ; with an introduction by Federigo Enriques ;. New York: Dover Publications.

Bonola, Roberto, H. S. Carslaw, Federico Enriques, John Bolyai, and Nicholas Lobachevski. Non-Euclidean Geometry: A Critical and Historical Study of Its Development ; Authorized English Translation With Additional Appendices By H. S. Carslaw ; With an Introduction By Federigo Enriques ;. New York: Dover Publications, 1955.

Bonola, Roberto, et al. Non-Euclidean Geometry: A Critical and Historical Study of Its Development ; Authorized English Translation With Additional Appendices By H. S. Carslaw ; With an Introduction By Federigo Enriques ;. New York: Dover Publications, 1955.