Valvasor, Johann Weichard, Freiherrn. Die Ehre des Herzogthumes Crain, Laybach, 1689.
Villard, L. Grottes du Vercors: Spélunca, 1896, vol. II., page 39.
Voigt, Joh. Carl Wilhelm. Mineralogische Reisen durch das Herzogthum Weimar, Weimar, 1785, vol. II., page 123.
Ward, J. Clifford. Nature, vol. XI., page 310.
White, Dr. C. A. Geological Reports of the State of Iowa, Des Moines, 1870, vol. I., page 80.
Whymper, Edward. Scrambles Amongst the Alps, London, John Murray, 1871.
Winchel, Alexander. Walks and Talks in the Geological Field, The Chautauqua Century Press, 1898.
Wise, T. A. Ice Making in the Tropics: Nature, Macmillan, London and New York, 1872, vol. V., pages 189-190.