APA (7th ed.) Citation

Ball James W., Blaine McCleske R., & U.S. Geological Survey. A new cation-exchange method for accurate field speciation of hexavalent chromium.

Chicago Style (17th ed.) Citation

Ball James W., Blaine McCleske R., and U.S. Geological Survey. A New Cation-exchange Method for Accurate Field Speciation of Hexavalent Chromium.

MLA (9th ed.) Citation

Ball James W., et al. A New Cation-exchange Method for Accurate Field Speciation of Hexavalent Chromium.

Warning: These citations may not always be 100% accurate.