The dust carried out of the desert:—

F. von Richtofen. China, Ergebnisse eigene Reisen und darauf gegründeten Studien, Berlin, 1877, vol. 1, pp. 56-125.

E. Hilgard. The Loess of the Mississippi Valley, Am. Jour. Sci., (3), vol. 18, 1879, pp. 106-112.

T. C. Chamberlin and R. D. Salisbury. Preliminary Paper on the Driftless Area of the Upper Mississippi Valley, 6th Ann. Rept. U. S. Geol. Surv., 1885, pp. 278-307.

E. E. Free. The movement of soil material by the wind, with a bibliography of eolian geology by S. C. Stuntz and E. E. Free, Bull. 68, U. S. Bureau of Soils, 1911, pp. 272, pls. 5.

M. Neumayr. Erdgeschichte, vol. 1, pp. 510-514.

E. de Martonne. Géographie physique, pp. 663-668.

Dunes:—

Vaughan Cornish. On the Formation of Sand-dunes, Geogr. Jour., vol. 9, 1897, pp. 278-309 (a most important paper).

F. Solger and Others. Dünenbuch. Enke, Stuttgart, 1910, pp. 373.