<https://www.airsoftsniperforum.com/threads/custom-90%EF%BF%BD-vsr-trigger.6449/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.airsoftsniperforum.com/threads/custom-90%EF%BF%BD-vsr-trigger.6449/page-3#post-69369>