Map of <a href="//commons.wikimedia.org/wiki/Solomon_Islands" title="Solomon Islands">Solomon Islands</a>.
<p>According to the <a rel="nofollow" class="external text" href="http://www.lib.utexas.edu/usage_statement.html?maps=yes">University of Texas</a>, "<i>most of the maps scanned by the University of Texas Libraries and served from this web site are in the public domain. No permissions are needed to copy them. You may download them and use them as you wish. A few maps are copyrighted, and are clearly marked as such.</i>". As the image, when downloaded from <a rel="nofollow" class="external text" href="http://www.lib.utexas.edu/maps/">here</a> was no tagged, the map is PD.
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Insofar the battle annotation make this necessary, I put this image in the public domain as well.
U.S. Central Intelligence Agency
1989
Modified version of <a rel="nofollow" class="external text" href="http://www.lib.utexas.edu/maps/australia/solomon_islands_pol89.jpg">Solomon Islands (Political) 1989</a> from <a rel="nofollow" class="external text" href="http://www.lib.utexas.edu/maps/solomon_islands.html">Perry-Castañeda Library Map Collection: Solomon Islands Maps</a>.