ZEMÁNEK, Petr. Principal solution in Weyl-Titchmarsh theory for second order Sturm-Liouville equation on time scales.
Electronic Journal of Qualitative Theory of Differential Equations. SZEGED, HUNGARY: UNIV SZEGED, BOLYAI INSTITUTE, 2017, Neuveden, č. 2, s. 1-18. ISSN 1417-3875. doi:10.14232/ejqtde.2017.1.2.