Phelps, G. (1929). Trade opportunity for automatic weighing machinery. [publisher not identified].
Chicago Style (17th ed.) CitationPhelps, Gordon. Trade Opportunity for Automatic Weighing Machinery. Washington, D.C.: [publisher not identified], 1929.
MLA (9th ed.) CitationPhelps, Gordon. Trade Opportunity for Automatic Weighing Machinery. [publisher not identified], 1929.
Warning: These citations may not always be 100% accurate.