APA (7th ed.) Citation

Northwestern Improvement Company, Ash, S. H., & Kudlich, R. H. (1930). Automatic derailing switch at Roslyn No. 3 mine, Northwestern Improvement Company, Roslyn, Wash. [publisher not identified].

Chicago Style (17th ed.) Citation

Northwestern Improvement Company, S. H. Ash, and Rudolf H. Kudlich. Automatic Derailing Switch at Roslyn No. 3 Mine, Northwestern Improvement Company, Roslyn, Wash. Washington, D.C.: [publisher not identified], 1930.

MLA (9th ed.) Citation

Northwestern Improvement Company, et al. Automatic Derailing Switch at Roslyn No. 3 Mine, Northwestern Improvement Company, Roslyn, Wash. [publisher not identified], 1930.