1. Nakhushev, A.M., On continuous differential equations and their difference analogs, Dokl. Akad. Nauk SSSR, 1988, vol. 300, no. 4, pp. 796–799.
2. Nakhushev, A.M., Uravneniya matematicheskoi biologii (Equations of Mathematical Biology), Moscow: Vyssh. Shk., 1995.
3. Nakhushev, A.M., On the positiveness of the operators of continuous and discrete differentiation that are rather important in fractional calculus and in the theory of mixed type equations, Differ. Uravn., 1998, vol. 34, no. 1, pp. 101–109.
4. Nakhushev, A.M., Drobnoe ischislenie i ego primenenie (Fractional Calculus and Its Applications), Moscow: Fizmatlit, 2003.
5. Volterra, V., Theory of Functionals and of Integral and Integro-Differential Equations, New York: Dover, 1959. Translated under the title: Teoriya funktsionalov, integral’nykh i integro-differentsial’nykh uravnenii, Moscow: Nauka, 1982.