Cho, Youngseon. <br/><br/>
Why?Numbers and Mathematics (Korean) : Why?수와 수학 / 
Youngseon Cho ; illustrated by Heeseok Song.  
 - Seoul, Korea :  Yearimdang,   2011. 
 - 190 p. 
<br/><br/><label>ISBN: </label>9788930231466 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Korean language materials.