TY  - BOOK
AU  - Gwak, Youngjik.
TI  - Wonderful gravity (Korean) : 왜 땅으로 떨어질까?
SN  - 9788901060989
PY  - 2007///
CY  - Seoul, Korea
PB  - Woongjin, 
KW  - Korean language materials
ER  -