identifier: geologicalsketch00agas https://archive.org/download/geologicalsketch00agas/geologicalsketch00agas.pdf IA contributor: Boston Public Library...
for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Geological_sketches_(IA_geologicalsketch00agas_4).pdf...
for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Geological_sketches_(IA_geologicalsketch00agas_3).pdf...
for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Geological_sketches_(IA_geologicalsketch00agas_0).pdf...
for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Geological_sketches_(IA_geologicalsketch00agas_2).pdf...
recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Geological_sketches,_2nd_series_(IA_geologicalsketch00agas_1).pdf...