Revision History for USGS 
  Crustal Studies Technical Letter Number 30

  Robert G. Rodriquez

  Calculations of Upper-Mantle Velocity from Published 
  Soviet Earthquake Data

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  Posted online at http://pubs.usgs.gov/misc/tl/0030/
  February 21, 2013

  Initial release in paper form
  April 15, 1965

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