@misc{indiciae46d4f6593830,
  title = {Solving groundwater flow problems by conjugate-gradient methods and the strongly implicit procedure},
  author = {Mary C. Hill},
  year = {2010},
  doi = {10.1029/wr026i009p01961},
  url = {https://pubs.usgs.gov/publication/70187667},
  note = {Source identifier: 70187667}
}