This database is compiled from these sources:

1. Catalog of relative positions of visual double stars, based on photographic observations performed since 1960 in Pulkovo on the 26-inch refractor (A.A.Kiselev, O.A.Kalinichenko, O.V.Kiyaeva, N.A.Shakht, L.G.Romanenko, I.S.Izmailov, O.P.Bykov, K.L.Maslennikov, E.A.Grosheva, D.L.Gorshanov), 2010

2. Catalog of relative positions of visual double stars, based on CCD observations performed since 1995 on Pulkovo 26-inch refractor (I.S.Izmailov), 2006, the first edition