1. S. Albeverio, J.E. Fenstad, R. Høegh-Krohn, and T. Lindstrøm, Nonstandard Methods in Stochastic Analysis and Mathematical Physics (Pure and Applied Mathematics. Academic Press, 1988, 2nd ed., Dover, 2009).
2. E.T. Bell, Men of Mathematics (Simon and Schuster, New York, 1937).
3. J.L. Bell, A Primer of Infinitesimal Analysis (Cambridge University Press, 1998).
4. V. Benci and M. Di Nasso, “A Ring Homomorphism is Enough to Get Nonstandard Analysis.” Bull. Belg. Math. Soc. Simon Stevin 10, 481–490, 2003.
5. V. Benci and M. Di Nasso, “A Purely Algebraic Characterization of the Hyperreal Numbers,” Proc. Amer. Math. Soc. 133(9), 2501–05 (2005).