Data sources:

6m: BVRc photometry by V.P.Goranskij and A.F.Valeev with the Russian 6-m telescope BTA + SCORPIO focal reducer (CCD EEV42-40).
A5: BVRc photometry by V.P.Goranskij with the SAI Crimean Station 50-cm Maksutov telescope AZT-5 and CCD Apogee Alta U8300 V=V(A5)+0.075; B=B(A5)+0.06.
AA: Photoelectric observations by V.P.Goranskij with NADIR WBVR photometer and 48-cm telescope of Tien-Shan Astronomical Observatory, Kazakhstan. Photoelectric observations by V.P.Goranskij and E.A.Karitskaya with WBVR photometer by V.G.Kornilov and 100-cm telescope of Tien-Shan Astronomical Observatory, Kazakhstan.
B: P.L.Bernacca, IAUC 3904 (1983)
BI: P.L.Bernacca, T.Iijima, R.Stagni, AsAp Vol.132, 8 (1984).
C6,C7,A7,47,VA,Pi: CCD observations by E.A.Barsukova, V.P.Goranskij and S.Yu.Shugarov using CCD SBIG ST-6 (C6), ST-7 (C7), Apogee-7 (A7), Apogee 47 (47), Princeton Instruments VersArray (VA) and Meade Pictor-416. 70-cm telescope of SAI Moscow Observatory; 60-cm reflector and 50-cm Maksutov telescope of SAI Crimean Station, Ukraine; 38-cm telescope of Crimean Astrophysical Observatory, Ukraine.
HS: R.K.Honeycut, E.M.Schlegel, IAUC 3899 (1983); PASP Vol.97, 300 (1985).
KKP: R.Kaur, B.Kumar, B.Paul, R.Sagar, ATel 1807 (2008)
KN: K.Kodaira, S.Nishimura, M.Kondo, S.Kikuchi, et al., PASJ Vol.37, 97 (1985).
pg: Photographic observations by V.P.Goranskij.
PS: Palomar Observatory Sky Survey.
R3: U.Kiziloglu, N.Kiziloglu, A.Baycal, S.K.Yerli, M.Ozbey, IBVS 5865, 2008 (corr.).
RW: R.W.Argyle, IAUC 3897 (1983)
SO: UBVRc photometry by V.P.Goranskij and E.A.Barsukova with CCD Elektronika-585, later CCD EEV 42-40 and SAO 1-m telescope.
TB: M.O.Arabaci, E.Beklen, B.Donnez, M.S.Niael, ATel 9618, 2016.