WSKG (https://wskg.org/npr_story_post/north-dakota-prison-officials-think-outside-the-box-to-revamp-solitary-confinement/chief-of-security-joe-charvat-walks-the-halls-of-the-state-penitentiarys-behavior-intervention-unit-biu-the-prisons-name-for-solitary-confinement-typically-there-are-about-20-inmates-in/)