Vectorized version of <a href="//commons.wikimedia.org/wiki/File:Aa_structure_function.jpg" title="File:Aa structure function.jpg">File:Aa structure function.jpg</a>
<a href="//commons.wikimedia.org/wiki/User:Ricordisamoa" title="User:Ricordisamoa">Ricordisamoa</a>
<span class="int-own-work" lang="en">Own work</span>