Suicide prevention by the Samaritans.
D000293:Adolescent; D000328:Adult; D002648:Child; D004739:England; D005069:Evaluation Studies as Topic; D006801:Humans; D008131:London; D008875:Middle Aged; D009938:Organizations; D012657:Self-Help Groups; D013406:Suicide, Attempted / Q000453:epidemiology / Q000517:prevention & control*; D014505:Urban Population