@misc{indiciae6bde81bfb5f7,
  title = {Plan of study for the regional aquifer-system analysis of the Appalachian Valley and Ridge, Piedmont, and Blue Ridge physiographic provinces of the eastern and southeastern United States, with a description of study-area geology and hydrogeology},
  author = {L.A. Swain and E. F. Hollyday and C. C. Daniel and O. S. Zapecza},
  year = {1991},
  doi = {10.3133/wri914066},
  url = {https://pubs.usgs.gov/publication/wri914066},
  note = {Source identifier: wri914066}
}