Cho, Youngseon. <br/><br/>
Why?Light and sound (Korean) : Why?빛과 소리 / 
Youngseon Cho ; illustrated by Youngho Lee. 
 - Seoul, Korea :  Yearimdang,  2011. 
 - 159 p. 
<br/><br/><label>ISBN: </label>9788930202664 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Korean language materials.