1. Ablowitz, M.J., Clarkson, P.A.: Solitons, Nonlinear Evolution Equations and Inverse Scattering. No. 149 in London Mathematical Society Lecture Note Series. Cambridge University Press, Cambridge, UK (1991)
2. Ablowitz M.J., Chakravarty S., Hahn H.: Integrable systems and modular forms of level 2. J. Phys. A 39(50), 15341–15353 (2006)
3. Berndt B.C.: Fragments by Ramanujan on Lambert series. In: Kanemitsu, S., Gyr, K. (eds) Number Theory and Its Applications, No. 2 in Dev. Math., pp. 35–49. Kluwer, Dordrecht (1999)
4. Berndt B.C.: Number Theory in the Spirit of Ramanujan, Student Mathematical Library, vol. 34. American Mathematical Society (AMS), Providence, RI (2006)
5. Berndt B.C., Bhargava S., Garvan F.G.: Ramanujan’s theories of elliptic functions to alternative bases. Trans. Am. Math. Soc. 347(11), 4163–4244 (1995)