ABSTRACT This paper presents the results of a combined spectroscopic and photometric study 20 contact binary systems: HV Aqr, OO Aql, FI Boo, TX Cnc, OT EE Cet, RW Com, KR V401 Cyg, V345 Gem, AK Her, V502 Oph, V566 V2612 V1363 Ori, V351 Peg, V357 Y Sex, V1123 Tau, W UMa, which was conducted in frame UMa Project. Together with 51 already covered by project an additional 67 existing literature, t...
