Yılmaz, BülentMert, Rukiye ÖztürkIsmailov, Zameddin İ.2021-11-032021-11-032019-02-01https://doi.org/10.31801/cfsuasmas.501414http://hdl.handle.net/20.500.12575/75855In the present paper, the aim is to described all selfadjoint extensions of the minimal operator generated by first order linear symmetric multipoint quasi-differential operator expression in the direct sum of weighted Hilbert spaces of vector-functions defined at the semi-infinite intervals by using the Calkin-Gorbachuk method. We have also examine the structure of the spectrum of such extensions.enSymmetric and selfadjoint differential operatorsMultipoint quasi-differential expressionDeficiency indicesArticle6819649722618-6470