reznickova1
Hi
Joomla copyrights is in Language is en-GB, then the following language sting is located in the file en-GB.mod_footer.ini that is located in the directory \language\en-GB folder
Find
MOD_FOOTER_LINE2="<a href="_QQ_"http://www.joomla.org"_QQ_">Joomla!</a> is Free Software released under the <a href="_QQ_"http://www.gnu.org/licenses/gpl-2.0.html"_QQ_">GNU General Public License.</a>"
You can also override it via Joomla language override options.