@misc{indiciaeea869be8176a,
  title = {Identifying calcium sources at an acid deposition-impacted spruce forest: A strontium isotope, alkaline earth element multi-tracer approach},
  author = {T.D. Bullen and S.W. Bailey},
  year = {2005},
  doi = {10.1007/s10533-004-2619-z},
  url = {https://pubs.usgs.gov/publication/70029633},
  note = {Source identifier: 70029633}
}