@article{EJDE_2016__2016__a0,
     author = {Ismailov,  Zameddin I. and Ipek,  Pembe},
     title = {Selfadjoint singular differential operators of first order and their spectrum},
     journal = {Electronic journal of differential equations},
     year = {2016},
     volume = {2016},
     zbl = {1330.47057},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2016__2016__a0/}
}