Edwards, C. W. (1963). A test of arithmetic principles, elementary form. University Microfilms.
Dyfyniad Arddull ChicagoEdwards, Charles Walter. A Test of Arithmetic Principles, Elementary Form. [Ann Arbor, Mich: University Microfilms, 1963.
Dyfyniad MLAEdwards, Charles Walter. A Test of Arithmetic Principles, Elementary Form. University Microfilms, 1963.
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