On generalized periodic solutions of linear differential equations of order n J. Ligęza — 1977 Annales Polonici Mathematici
Cauchy's problem for systems of linear differential equations with distributional coefficients J. Ligęza — 1975 Colloquium Mathematicae
On generalized solutions of some differential non-linear equations of order n J. Ligęza — 1975 Annales Polonici Mathematici