RT Journal Article SR Electronic(1) A1 Georgiev, G.YR 1999 T1 Understanding of Petroleum System-Play Concept and Assessment for Bulgaria JF , VO OP SP cp-132-00464 DO https://doi.org/10.3997/2214-4609.201408061 PB European Association of Geoscientists & Engineers, SN 2214-4609, AB , UL https://www.earthdoc.org/content/papers/10.3997/2214-4609.201408061