We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleH.M. Prison, Grendon.AuthorsSNELL, H KPublicationBritish medical journal, 1962, Vol 2, Issue 5307, p789ISSN0007-1447Publication typeJournal ArticleDOI10.1136/bmj.2.5307.789