1. Linear ordinary differential equations with Laplace-Stieltjes transforms as coefficients;Archangelo;Trans. Amer. Math. Soc.,1974
2. J. D' Archangelo and P. Hartman, Integration of ordinary linear differential equations by Laplace-Stieltjes transforms, ibid.
3. On differential equations and the function J2μ + K2μ;Hartman;Amer. J. Math.,1961
4. On differential equations, Volterra equations and the functions J2μ + Y2μ;Hartman;Ibid.,1973
5. P. Hartman, Ordinary Differential Equations, Baltimore (1973).