Related Clues:

• Refinery flow
• Biggest export of 99-Down
• The Da Vinci coat?
• Kind of slick
• Canadian resource
• Source of Rockefeller's wealth
• Gusher flow
• Slick material
• Many a MoMA piece
• Upton Sinclair novel
• Rockefeller's biz
• Smear, like paint
• ''Crude'' fuel
• Product of a field of dreams?
• Gallery hanging