Trávníček, Stanislav; Zaoral, Jaroslav:
Transformation der Lösungen der Systeme von vier linearen Differentialgleichungen 1. Ordnung.
(German) [Transformation of solutions of systems of four linear differential equations of first order].Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica-Physica-Chemica,
vol. 11
(1971),
issue 1,
pp. 119-129