Data sources:

VSO: VSOLJ data.
DEA: H.W.Duerbeck, S.Benetti, A.Gautschy, A.M.van Genderen, C.Kemper, W.Liller, T.Thomas, AJ Vol.114, 1657 (1997). H.W.Duerbeck, W.Liller, C.Sterken, S.Benetti, A.M.van Genderen, J.Arts, J.D.Kurk, M.Janson, T.Voskes, E.Brogt, AJ Vol.119, 2360 (2000).
KGK: S.Kimeswenger, H.Gratl, F.Kerber, P.Fouque, S.Kohle, S.Steele, IAUC 6608 (1997).
L,Lc: V.P.Arkhipova, R.I.Noskova, PAZh Vol.23, 709 (1997). V.P.Arkhipova, V.F.Esipov, R.I.Noskova, G.V.Sokol, A.M.Tatarnikov, V.I.Shenavrin, B.F.Yudin, U.Munari, M.Rejkuba, PAZh Vol.24, 297 (1998). V.P.Arkhipova, V.F.Esipov, G.V.Sokol, PAZh Vol.24, 431 (1998). V.P.Arkhipova, R.I.Noskova, V.F.Esipov, G.V.Sokol, Astron. Letters V.25, 615 (1999). [Data in CDS/VizieR II/229/table (L - observations with Lyuty's UBV photometer, Lc - VR observations with CCD SBIG ST-6)].
JD: G.Jakoby, O.De Marco, D.Willmarth, A.Saha, D.Harmer, D.Sawyer, IAUC 7065 (1998).
LDM: W.Liller, H.W.Duerbeck, A.van der Meer, A.van Genderen, IAUC 7049 (1998).
ShV: Photoelectric observations of V.P.Goranskij and A.V.Kusakin with UBV photometer by S.Shugarov and I.Volkov using 60-cm, 125-cm telescope of SAI Crimean Station, Ukraine; 38-cm telescope of Crimean Astrophysical Observatory; 70-cm telescope of SAI Moscow Observatory; 60-cm telescope of INASAN Zvenigorod Station in Moscow region.
AA: Photoelectric observations by V.P.Goranskij, E.A.Karitskaya, A.V.Kusakin and T.M.Pogrosheva with WBVR photometer by V.G.Kornilov and 100-cm telescope of Tien-Shan Astronomical Observatory, Kazakhstan.
C6,C7: Observations by V.P.Goranskij using CCD SBIG ST-6 and ST-7 with 60-cm, 125-cm telescopes of SAI Crimean Station, 38-cm telescope of Crimean Astrophysical Observatory, 70-cm telescope of SAI Moscow Observatory and INASAN Zvenigorod Station in Moscow region.
GH: Hickel, Kyi: Kyiota, Oud: Ouda.