Circuit of Europe during the International Touring Aircraft Contest in 1932 (<a href="https://en.wikipedia.org/wiki/Challenge_International_de_Tourisme_1932" class="extiw" title="en:Challenge International de Tourisme 1932">en:Challenge International de Tourisme 1932</a>)
derivative work: <a href="//commons.wikimedia.org/wiki/User:Pibwl" title="User:Pibwl">Pibwl</a>
Own work, derivative of <a href="//commons.wikimedia.org/wiki/File:Blank_map_of_Europe_in_1920.svg" title="File:Blank map of Europe in 1920.svg">File:Blank_map_of_Europe_in_1920.svg</a>