- eBookEurypterids of the Devonian Holland Quarry Shale of OhioErik Norman Kjellesvig-Waering
- eBookPennsylvanian invertebrates of the Mazon Creek Area, IllinoisErik Norman Kjellesvig-Waering
- eBookPennsylvanian invertebrates of the Mazon Creek Area, IllinoisErik Norman Kjellesvig-Waering
- eBookEurypterids of the Devonian Holland Quarry Shale of OhioErik Norman Kjellesvig-Waering