Title from PDF title screen (viewed September 01, 2004).
"April 1999."
System details (note)
Mode of access: Internet from the GPO permanent archive. Address as of 9/01/04: http://permanent.access.gpo.gov/waterusgsgov/water.usgs.gov/pubs/fs/FS-040-99/pdf/fs-040-99.pdf; current access is available via PURL.
Title
Puerto Rico.
Imprint
[Reston, Va.] : U.S. Dept. of the Interior, U.S. Geological Survey, [1999]
Mode of access: Internet from the GPO permanent archive. Address as of 9/01/04: http://permanent.access.gpo.gov/waterusgsgov/water.usgs.gov/pubs/fs/FS-040-99/pdf/fs-040-99.pdf; current access is available via PURL.