Sources.

6m: E.A.Barsukova, V.P.Goranskij and A.F.Valeev, CCD V observations with the Russian 6-m telescope and SCORPIO focal reducer.
A5: V.P.Goranskij, UBV(RI)c photometry with the 50 cm meniscus Maksutov telescope of the Moscow University Crimean Station and Apogee Alta U8300 CCD.
AF: V.P.Goranskij, UBV(RI)c photometry with the 60-cm Zeiss telescope of the Crimean Station of the Moscow University and CCD FLI PL9104220.
Ak: V.P.Goranskij using guide of SAO Zeiss-1000 with the Atik 414ex CCD.
An: Antares, Astronomical club, Demitrovgrad, Facebook.
As: A.V.Zharova, BV(RI)c photometry with the 60 cm Zeiss telescope of the Moscow University Crimean Station and Apogee Aspen CCD.
it: V.P.Goranskij, eye estimates with the 25 cm reflector and the electronic image tube equipped with a microchannel plate, ~Rc band.
KNT: A.Kurtenkov, M.Napetova, T.Tomov, ATel#10725, 2017.
MH: U.Munari, F.-J.Hambsch, A.Frigo, F.Castellani, G.La Mura, G.Traven, M.Ozbi Arabaci, T.Saguner, ATel#10572, 2017.
MM: V.P.Goranskij, UBV(RI)c photometry with the SAO RAS 1 m Zeiss telescope and MMPP photometer polarimeter.
MO: U.Munari, P.Ochner, F.-J.Hambsch, A.Frigo, F.Castellani, A.Milani, P.Valisa, A.Vagnozzi, ATel#10736, 2017.
SK: K.Z.Stanek, C.S.Kohanek, L.Chomiuk, J.Strader, J.S.Brown, T.W.-S.Holoien, J.V.Shields, T.A.Thompson, B.J.Shappee, J.L.Prieto, Subo Dong, ATel#10523, 2017.
SO: V.P.Goranskij with the 1 m Zeiss telescope of SAO RAS and CCD UBVRcIc photometer.