<p>learning about 'linear holding' patterns for air traffic control <a href="https://nats.aero/blog/2016/05/is-this-the-end-of-stack-holding/" target="_blank" rel="nofollow noopener" translate="no"><span class="invisible">https://</span><span class="ellipsis">nats.aero/blog/2016/05/is-this</span><span class="invisible">-the-end-of-stack-holding/</span></a></p>
