Sources.

A5: V.P.Goranskij with the 50 cm meniscus Maksutov telescope of the SAI Crimean Station and Apogee Alta U8300 CCD.
KE: B.Kumar, Ch.Eswaraiah, A.Singh, D.K.Sahu, G.C.Anupama, K.S.Kawabata, M.Yamanaka, I.Otsubo, S.B.Pandey, T.Nakaoka, M.Kawabata, A.Aryan, H.Akitaya, MNRAS V.488, 3089, 2019.
MM: V.P.Goranskij with the 1 m Zeiss telescope of SAO RAS and MMPP UBVRcIc photometer polarimeter.
PC: J.L.Prieto, Ping Chen, Subo Dong, B.J.Shappee, M.Seibert, D.Bersier, T.W.-S.Holoien, C.S.Kochanek, K.Z.Stanek, T.A.Thompson. Research Notes of the AAS, V.1, No.1, 2017.
SO: V.P.Goranskij with the 1 m Zeiss telescope of SAO RAS and CCD UBVRcIc photometer.