1. California earthquake of April 18, 1906: 25 (1908).
2. Report of the California Earthquake Commission 1: 434 (1908).
3. Report of the California Earthquake Commission 1: 220 (1908).
4. Report of the California Earthquake Commission 1: 25 (1908).
5. Gilbert, G. K., U. S. Geological Survey Monograph 1 362 (1890).