Cauchy type problems of linear Riemann-Liouville fractional differential   equations with variable coefficients
  The existence of solutions to Cauchy type problems of linear Riemann-Liouville fractional differential equations with variable coefficients is considered in a space of integrable functions. First, we consider the existence and uniqueness of solution for a Cauchy type problem with special initial conditions in the space of integrable functions. Then we provide an example of the problem that has no solution in the space of integrable functions. We give a solving method and a representation of solutions for the Cauchy type problem. Last we give some examples. 
Myong-Ha Kim, Guk-Chol Ri, Gum-Song Choe and Hyong-Chol O
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