Hong, Sungmin et al. History of Ancient Copper Smelting Pollution During Roman and Medieval Times Recorded in Greenland Ice (англ.) // Science : journal. — 1996. — Vol. 272, no. 5259. — P. 246–249 [p. 248]. — doi:10.1126/science.272.5259.246. — Bibcode: 1996Sci...272..246H.
Hong, Sungmin et al. History of Ancient Copper Smelting Pollution During Roman and Medieval Times Recorded in Greenland Ice (англ.) // Science : journal. — 1996. — Vol. 272, no. 5259. — P. 246–249 [p. 248]. — doi:10.1126/science.272.5259.246. — Bibcode: 1996Sci...272..246H.