APA (7th ed.) Citation
Fehr, H. F. (1940). A Study of the number concept of secondary school mathematics.
Chicago Style (17th ed.) Citation
Fehr, Howard Franklin. A Study of the Number Concept of Secondary School Mathematics. New York, 1940.
MLA (9th ed.) Citation
Fehr, Howard Franklin. A Study of the Number Concept of Secondary School Mathematics. 1940.
Warning: These citations may not always be 100% accurate.