동영상1:http://serviceapi.nmv.naver.com/flash/NFPlayer.swf?vid=37FD0B399F9C56E95B8AA138C997517B84EE&outKey=V122801437814c11fada9986309c0aeaeee7dc4becae395ce51be986309c0aeaeee7d
 

동영상2:http://www.edunet4u.net/teacher6/directory/directoryList.do?pagingId=directoryPage&viewType=directoryDetail&org_cd=A000800002&data_no=795971&seq_no=1&rn=1&clasDivTypeDv=1&lvl1TypeCd=1&lvl2TypeCd=4&lvl3TypeCd=5&lvl4TypeCd=0&q_from=naver