참고문헌
- 홍현철, 변대준, '온달굴의 지형와 특성에 관한 연구', 제34호, 6월, 1993년, pp.23-29
- http://www.tourguide.co.kr/local/local_detail.htm?pCod e=LANDCAVE0008
- http://www.njoyschool.net/chehum/chehum_theme_vie w_contents.asp?contents_cd=89
The black pollution that was able to include green pollution to appear for the intensity of light by an illumination institution is what after all I cannot ignore, and it may be said that chase thing damage by the isolation action that is white pollution done a long story in this outside a certain range by air quality change, dried present situation is really the environmental disruption by development and a damage phenomenon. If I am replaced in winker and I install a sensor light in the outlet by addition and use the electricity illumination that I installed for a tourist in the cave, it is expected that I can be available all the time that it is possible for electricity reduction more than the present and watches tourist passage plan private business Electric illumination in the cave for the environmental save in the cave because it is possible for more electricity reduction to be particularly off-season than on-season.