- E-bookThe Earth as Modified by Human ActionGeorge P. Marsh
- E-bookMan and Nature; Or, Physical Geography as Modified by Human ActionGeorge P. Marsh
- E-bookMan and Nature; Or, Physical Geography as Modified by Human ActionGeorge P. Marsh
- E-bookThe Whelps of the WolfGeorge P. Marsh
- E-bookMan and NatureGeorge P. Marsh
- E-bookThe Earth as Modified by Human ActionGeorge P. Marsh