1. Miller KS, Ross B (2003) An introduction to the fractional calculus and fractional differential equations. John-Wily and Sons. Inc., New York
2. Oldham KB, Spanier I (1974) The fractional calculus. Academic Press, New York and London
3. Podlubny I (1999) Fractional differential equations. Academic Press, San Diego
4. Kilbas AA, Srivastava HM, Trujillo JJ (2006) Theory and applications of fractional differential equations, North-Holland mathematics studies, vol 204. Elsevier Science B.V, Amsterdam
5. Zadeh LA (1965) Fuzzy sets. Inf Control 8(3):338–353