APA (7th ed.) Citation

Helsley, R. J. (1985). Terry sandstone member of the Pierre Shale, Upper Cretaceous, Spindle field, Denver Basin, Colorado. [publisher not identified].

Chicago Style (17th ed.) Citation

Helsley, Robert James. Terry Sandstone Member of the Pierre Shale, Upper Cretaceous, Spindle Field, Denver Basin, Colorado. [Place of publication not identified]: [publisher not identified], 1985.

MLA (9th ed.) Citation

Helsley, Robert James. Terry Sandstone Member of the Pierre Shale, Upper Cretaceous, Spindle Field, Denver Basin, Colorado. [publisher not identified], 1985.