@misc{indiciaea9931b97a2d2,
  title = {Azomethine H colorimetric method for determining dissolved boron in water},
  author = {R.R. Spencer and D. E. Erdmann},
  year = {2002},
  doi = {10.1021/es60156a008},
  url = {https://pubs.usgs.gov/publication/70012562},
  note = {Source identifier: 70012562}
}