http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Earthquakes in the United States, January-March 1974
by C.W. Stover, R.B. Simon, and W.J. Person.
Includes bibliographical references (page 18).
Circular (Geological Survey (U.S.)) ; 723-A