Patent of Georgy Bozhinov
Unknown author<span style="display: none;">Unknown author</span>
<a href="https://bg.wikipedia.org/wiki/%D0%9C%D1%83%D0%B7%D0%B5%D0%B9_%D0%BD%D0%B0_%D0%B0%D0%B2%D0%B8%D0%B0%D1%86%D0%B8%D1%8F%D1%82%D0%B0_(%D0%9F%D0%BB%D0%BE%D0%B2%D0%B4%D0%B8%D0%B2)" class="extiw" title="bg:Музей на авиацията (Пловдив)"> Музей на авиацията, Крумово</a>