(1904). Vol. 33, № 1-6, Vol. 34, № 1-6; American Geologist. 1904.
Cita Chicago (17th ed.)Vol. 33, № 1-6, Vol. 34, № 1-6; American Geologist. 1904, 1904.
Cita MLA (9th ed.)Vol. 33, № 1-6, Vol. 34, № 1-6; American Geologist. 1904, 1904.
Atenció: Aquestes cites poden no estar 100% correctes.