@misc{indiciae415a4c1c8834,
  title = {An international standard for a mapping method in bird census work recommended by the International Bird Census committee},
  author = {S. Svensson and K. Williamson and C. Ferry and A.H. Joensen and D. Lea and H. Oelke and C.S. Robbins},
  year = {1970},
  url = {https://pubs.usgs.gov/publication/5223002},
  note = {Source identifier: 5223002}
}