Lopushansky, A.O., et al. “Two Definitions of the Generalized Cauchy Problem for Semi-Linear Diffusion Equation With Fractional Derivative With Respect to Time”. Carpathian Mathematical Publications, vol. 4, no. 1, June 2012, pp. 72-82, https://ktipe.pnu.edu.ua/index.php/cmp/article/view/2408.