@inbook{Ingersoll1880whatmust,
  author    = {Ingersoll, Robert G.},
  title     = {What Must We Do To Be Saved?},
  booktitle = {The Works of Robert G. Ingersoll, Dresden Edition},
  publisher = {C. P. Farrell},
  address   = {New York},
  volume    = {1},
  year      = {1880},
  url       = {https://thegreatagnostic.com/works/what-must-we-do-to-be-saved/},
  note      = {Public domain. Dresden Edition identifier: dresden:vol-1:what-must-we-do-to-be-saved}
}