United States. Federal Board for Vocational Education. (1919). Unit course: Mathematics I, use of slide rule, trial edition. GPO.
Chicago Style (17th ed.) CitationUnited States. Federal Board for Vocational Education. Unit Course: Mathematics I, Use of Slide Rule, Trial Edition. [Washington]: GPO, 1919.
MLA (9th ed.) CitationUnited States. Federal Board for Vocational Education. Unit Course: Mathematics I, Use of Slide Rule, Trial Edition. GPO, 1919.
Warning: These citations may not always be 100% accurate.