1. Radhey Shyam Kaushal, Structural analogy in understanding nature (Anamaya Publishers, New Delhi, 2003)
2. See for example, J N Kapur, Mathematical models in biology and medicine (Affiliated East-West Press, Pvt. Ltd., New Delhi, 1985)
3. J D Murray, Mathematical biology (Springer-Verlag, New York, 1993)
4. C S Bertuglia and F Vaio, Nonlinearity, chaos and complexity: The dynamics of natural and social systems (Oxford University Press, New York, 2005)
5. A Coely et al (Eds), Bäcklund and Darboux transformations (Amer. Math. Soc., Providence, RI, 2001)