Note 3 — Chapter I · PETROLEUM By John D. Northrop[1]
Reading edition
Arnold, Ralph: “The World’s Oil Supply”: Report Am. Min. Cong., 19th annual session, 1917, pp. 485-486.
Reading edition
Arnold, Ralph: “The World’s Oil Supply”: Report Am. Min. Cong., 19th annual session, 1917, pp. 485-486.