Hughes, T.M., 1893, Note on Walnut Canyon and its cliff dwellings, in Emmons, S.F., ed., Geological guide book of the Rocky Mountain excursion - Congres Geologique International, Compte Rendu de la 5me Session, Washington, 1891: Washington, D.C., Imprimerie du Gouvernement [U.S. Government Printing Office], Part 4B, p. 475-476.
