- E-bookEurypterids of the Devonian Holland Quarry Shale of OhioErik Norman Kjellesvig-Waering
- E-bookPennsylvanian invertebrates of the Mazon Creek Area, IllinoisErik Norman Kjellesvig-Waering
- E-bookPennsylvanian invertebrates of the Mazon Creek Area, IllinoisErik Norman Kjellesvig-Waering
- E-bookEurypterids of the Devonian Holland Quarry Shale of OhioErik Norman Kjellesvig-Waering