1. Ayoub, R. (1980). Paolo Ruffini’s contributions to the quintic. Archive for History of Exact Sciences, 23(3), 253–277.
2. Baltus, C. (2003). Continued fractions and the first proofs that pi is irrational. In Communications in the Analytic Theory of Continued Fractions (Vol. XI, pp. 5–24).
3. Barnett, J. H. (2004). Enter, stage center: The early drama of the hyperbolic functions. Mathematics Magazine, 77(1), 15–30.
4. Berggren, L., Borwein, J., & Borwein, P. (Eds.). (1997). Pi: A source book. New York: Springer.
5. Bermúdez, C. G. (2009). Georg Cantor. Sistemas de números y conjuntos. Universidad de A Coruña.