Own work  using: <a rel="nofollow" class="external autonumber" href="https://www.sofia.bg/documents/20182/593915/%D0%93%D0%B5%D1%80%D0%B1+%D0%BD%D0%B0+%D0%A1%D0%BE%D1%84%D0%B8%D1%8F+-+%D1%86%D0%B2%D0%B5%D1%82%D0%BD%D0%BE+%D0%B8%D0%B7%D0%BE%D0%B1%D1%80%D0%B0%D0%B6%D0%B5%D0%BD%D0%B8%D0%B5+%D0%B7%D0%B0+%D0%BF%D0%B5%D1%87%D0%B0%D1%82.pdf/a0fd1eea-55e4-4cac-a960-c78cd8c1c516">[2]</a>, based on <a rel="nofollow" class="external autonumber" href="https://www.sofia.bg/en/web/tourism-in-sofia/coat-of-sofia">[3]</a>