@misc{indiciaeb9897a4f8407,
  title = {Contributions to economic geology, 1905: Portland, natural, and Puzzolan cements},
  author = {E.C. Eckel and Henry Landes},
  year = {1906},
  doi = {10.3133/b285i},
  url = {https://pubs.usgs.gov/publication/b285I},
  note = {Source identifier: b285I}
}