1. For example, see http://planetmath.org/encyclopedia/JensensInequality.html .
2. Abe, S.: Stability of Tsallis entropy and instabilities of R´enyi and normalized Tsallis entropies: A basis for q-exponential distributions. Phys. Rev. E 66, 046134 (2002)
3. Abe, S., Kaniadakis, G., Scarfone, A.M.: Stabilities of generalized entropies. J. Phys. A: Math. Gen. 37, 10,513–10,519 (2004)
4. Balmforth, N.J., Provenzale, A., Spiegel, E.A., Martens, M., Tresser, C., Wu, C.W.: Red spectra from white and blue noise. Proc. R. Soc. London, Ser. B 266, 311–314 (1999)
5. Beck, C., Schl¨ogl, F.: Thermodynamics of chaotic systems, an introduction. Cambridge University Press, Cambridge, UK (1997)