Ayres, Leonard Porter,  1879-1946. <br/><br/>
The effect of promotion rates on school efficiency, 
by Leonard P. Ayres ... 
 - New York City,  Division of Education, Russell Sage Foundation,  1913. 
 - 13 p.  diagrs.  23 cm. 
 - [Russell Sage Foundation, New York. Dept. of Child Hygiene. Pamphlet]  E130 .
<br/><br/> Reprinted from the American school board journal, May, 1913. 
<br/><br/><label>LCCN: </label>e  13000939  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Promotion (School)<br/>School attendance.
<br/><br/><label>LC Class. No.: </label>LB3063  / .A9