@misc{indiciaeb2bef8cd5a72,
  title = {Portland cement mortars and their constitutent materials, results of tests made at the structural materials testing laboratories, Forest Park, St. Louis, Missouri, 1905-1907},
  author = {Richard Lewis Humphrey and William Jordan},
  year = {1908},
  doi = {10.3133/b331},
  url = {https://pubs.usgs.gov/publication/b331},
  note = {Source identifier: b331}
}