United States. Bureau of Mines. (1938). Permissible electrically operated post drills and drilling machines. [s.n.].
Chicago Style (17th ed.) CitationUnited States. Bureau of Mines. Permissible Electrically Operated Post Drills and Drilling Machines. [Washington]: [s.n.], 1938.
MLA (9th ed.) CitationUnited States. Bureau of Mines. Permissible Electrically Operated Post Drills and Drilling Machines. [s.n.], 1938.
Warning: These citations may not always be 100% accurate.