An index of oil-shale patents.
Series: United States. Bureau of Mines. Bulletin; 468; Bulletin (United States. Bureau of Mines) ;; 468.
Publisher: U.S. Govt. Print. Off.
Published: 1949
Place of publication: Washington
Language: eng
Number of pages: 650
Subjects: Petroleum -- Refining.; Petroleum -- Patents.
Other titles: Shale-oil patents.