Chen, Y., Ma, Z., Yu, D., Jiang, Z., Wang, B., & Yuan, L. (2022). Geographical distribution of trace elements (selenium, zinc, iron, copper) and case fatality rate of COVID-19: a national analysis across conterminous USA. Environmental Geochemistry and Health, 44, 4423–4436. https://doi.org/10.1007/s10653-022-01204-0