How to remove unused entries on page head

I am no longer using summer notes, medium notes or backgroundvideo. But I could not get rid of below given entries from my layout page. Any idea why they reappear and how to remove?

 <script src="/dmxAppConnect/dmxSummernote/dmxSummernote.js" defer=""></script>
<link rel="stylesheet" href="/dmxAppConnect/dmxMediumEditor/dmxMediumEditor.css" />
<script src="/dmxAppConnect/dmxMediumEditor/dmxMediumEditor.js" defer=""></script>
<link rel="stylesheet" href="/dmxAppConnect/dmxMediumEditor/medium-editor.css" />
<script src="/dmxAppConnect/dmxMediumEditor/medium-editor.js" defer=""></script>
<link rel="stylesheet" href="/dmxAppConnect/dmxMediumEditor/themes/default.css" />
<script src="/dmxAppConnect/dmxBackgroundVideo/dmxBackgroundVideo.js" defer=""></script>