RT Journal Article SR Electronic(1) A1 P. Lockridge, J.YR 1994 T1 Shallow upper Cretaceous Niobrara Gas Fields in the Eastern Denver Basin, Colorado, USA JF , VO OP SP cp-56-00023 DO https://doi.org/10.3997/2214-4609.201407550 PB European Association of Geoscientists & Engineers, SN 2214-4609, AB , UL https://www.earthdoc.org/content/papers/10.3997/2214-4609.201407550