[1] J. Kurzweil: Generalized Ordinary Differential Equations and Continuous Dependence on a Parameter. Czech. Math. Јournal 7 (82), 1957, 3, 418-449. MR 0111875 | Zbl 0090.30002

[2] J. Jarník, J. Kurzweil: On Continuous Dependence on a Parameter. Contributions to the Theory of Non-Linear Oscillations 5, 25-35. MR 0132232

[3] J. Kurzweil: Addition to my Paper „Generalized Ordinary Differential Equations and Continuous Dependence on a Parameter". Czech. Math. Јournal 9 (84), 1959, 4, 564-573. MR 0111882