Allen, Richard.Rapid magnitude determination for earthquake early warning // The Many Facets of Seismic Risk (неопр.) / G. Manfredi, M.R. Pecce, and A. Zollo. — 2004. — С. 15—24. — (Proceedings of the "Workshop on Multidisciplinary Approach to Seismic Risk Problems", hold in Sant'Angelo dei Lombardi, September 22, 2003). Архивировано 1 июля 2019 года.
Allen, Richard.Rapid magnitude determination for earthquake early warning // The Many Facets of Seismic Risk (неопр.) / G. Manfredi, M.R. Pecce, and A. Zollo. — 2004. — С. 15—24. — (Proceedings of the "Workshop on Multidisciplinary Approach to Seismic Risk Problems", hold in Sant'Angelo dei Lombardi, September 22, 2003). Архивировано 1 июля 2019 года.