radiotimes Mark Gatiss and Steven Moffat reveal where Sherlock could go in series 5
guardian Sherlock finale trumped by Russian leak online
telegraph The Final Problem, review: 'an exhilarating thrill-ride'
guardian Sherlock recap: series four, episode three – The Final Problem
cultbox ‘The Final Problem’ was a great way to end the show
vox “The Final Problem” might be the series finale. If it is, it's a huge disappointment.