![](/img/cover-not-exists.png)
A Research in Mental Arithmetic Involving Subtraction
Herbert T. Olander and Betty Irene BrownVolume:
53
Language:
english
Pages:
6
Journal:
The Journal of Educational Research
DOI:
10.2307/27588320
Date:
November, 1959
File:
PDF, 995 KB
english, 1959