Rickett, B. I.; Payer, J. H. (1995). “Composition of Copper Tarnish Products Formed in Moist Air with Trace Levels of Pollutant Gas: Hydrogen Sulfide and Sulfur Dioxide/Hydrogen Sulfide”. 《Journal of the Electrochemical Society》 142 (11): 3723–3728. Bibcode:1995JElS..142.3723R. doi:10.1149/1.2048404.
Schmitz, Christopher (1986). “The Rise of Big Business in the World, Copper Industry 1870–1930”. 《Economic History Review》. 2 39 (3): 392–410. doi:10.1111/j.1468-0289.1986.tb00411.x. JSTOR2596347.
Rickett, B. I.; Payer, J. H. (1995). “Composition of Copper Tarnish Products Formed in Moist Air with Trace Levels of Pollutant Gas: Hydrogen Sulfide and Sulfur Dioxide/Hydrogen Sulfide”. 《Journal of the Electrochemical Society》 142 (11): 3723–3728. Bibcode:1995JElS..142.3723R. doi:10.1149/1.2048404.
Schmitz, Christopher (1986). “The Rise of Big Business in the World, Copper Industry 1870–1930”. 《Economic History Review》. 2 39 (3): 392–410. doi:10.1111/j.1468-0289.1986.tb00411.x. JSTOR2596347.
merriam-webster.com
“Copper”. Merriam-Webster Dictionary. 2018. 2018년 8월 22일에 확인함.