@misc{indiciaeb36fcd159729, title = {U.S. Geological Survey heavy metals program progress report 1968 --Topical studies}, author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey}, year = {1969}, doi = {10.3133/cir622}, url = {https://pubs.usgs.gov/publication/cir622}, note = {Source identifier: cir622} }