School Mathematics Study Group, <br/><br/>
Mathematics for Junior High School,V1 Part 2  Textual Documents 
School Mathematics Study Group 
 - United States of America:  Yale University Press.,  1961. 
 - 258-462p. 
 - Teacher`s Commentary,4. .
<br/><br/><label>Subjects--Index Terms: </label>Circles,Mathematical Systems,Ratios,Percents and Decimals,Parallelogram