1. Jae-chun Lee, Jinki Jeong, Byung-su Kim, et. al., 2010 : Development of Technology for the Recycling of Urban Ore, Korea Institute of Geoscience and Mineral Resources, pp.31.
2. Ministry of Environment, http://www.me.go.kr/wonju/web/board/read.do?menuId=1032&boardMasterId=232&boardCategoryId=305&boardId=293348, June 14, 2022.
3. A review: On the development of low melting temperature Pb-free solders
4. H. Takahashi, T. Tanaka, M. Hamada, et. al., 2009 : Novel Recycle System of Solder Paste, 10th Int. Symp. on East Asian Res. Recycl. Tech., pp.761-764.
5. A Novel Cyclic Process Involving Zinc for Separating Silver from Lead-Free Solder Residue