1. I. Podlubny, Fractional differential equations, Academic Press, San Diego, CA, 1999.
2. K. B. Oldham and J. Spanier, The fractional calculus, Academic Press, New York, London, 1974.
3. K. S. Miller and B. Ross, An introduction to the fractional calculus and fractional differential equations, Wiley, New York, 1993.
4. A. A. Kilbas, H. M. Srivastava and J. J. Trujillo, Theory and applications of fractional differential equations, Elsevier, Amsterdam, 2006.
5. R. Gorenflo and F. Mainardi, Fractional calculus: integral and differential equations of fractional order, In: A. Carpinteri, F. Mainardi (Eds.), Fractals and Fractional Calculus in Continuum Mechanics, Springer-Verlag, Wien/New York, 1997, pp. 223–276.