Note 31 — III A CENTURY OF GEOLOGY.—STEPS OF PROGRESS IN THE INTERPRETATION OF LAND FORMS
Reading edition
Davis, W. M., The rivers and valleys of Pennsylvania, Nat. Geogr. Mag., 1, 183–253, 1889.
——, The rivers of northern New Jersey with notes on the classification of rivers in general, ibid., 2, 81–110, 1890.