Description
Item Description:Electronic resource.
Physical Description:volumes : digital, PDF files.
Also issued in print.
Publication Frequency:Three issues yearly, 2013-
Format:Mode of access: Internet via the NGA web site and GPO Permanent Archive. Addresses as of 2/06/2009: http://www1.nga.mil/Pages/Default.aspx for current issues, https://permanent.fdlp.gov/lps107453/pathfinder, for archived issues ; current access is available via PURLs.
ISSN:1948-4569