1. On the singular Cauchy problem;Carroll;J. Math. Mech.,1963
2. A solution of the singular initial value problem for the Euler-Poisson-Darboux equation;Diaz,1953
3. A singular abstract Cauchy problem;Donaldson,1970
4. An operational calculus for a class of abstract operator equations;Donaldson;J. Math. Anal. Appl.,1972