Zettl, Anton; Sun, Jiong Survey article: Self-adjoint ordinary differential operators and their spectrum. (English) Zbl 1369.47057 Rocky Mt. J. Math. 45, No. 3, 763-886 (2015). MSC: 47E05 47-02 PDFBibTeX XMLCite \textit{A. Zettl} and \textit{J. Sun}, Rocky Mt. J. Math. 45, No. 3, 763--886 (2015; Zbl 1369.47057) Full Text: DOI Euclid
Wang, Aiping; Sun, Jiong; Zettl, Anton Two-interval Sturm–Liouville operators in modified Hilbert spaces. (English) Zbl 1116.47040 J. Math. Anal. Appl. 328, No. 1, 390-399 (2007). Reviewer: Hector O. Fattorini (Los Angeles) MSC: 47E05 34B24 47B25 34L05 PDFBibTeX XMLCite \textit{A. Wang} et al., J. Math. Anal. Appl. 328, No. 1, 390--399 (2007; Zbl 1116.47040) Full Text: DOI