Complex sentence: Sigma Terra Corps, Sigma TC, is a Swedish science fiction club, founded 5 December 1976 in Saltsjöbaden by Wolf von Witting, Jörg Litschke and Johan Richter.
Split into simpler sentences: Sigma Terra Corps is a Swedish science fiction club located in Saltsjöbaden. Commonly known by its abbreviation Sigma TC, founded December 5,1976 by Wolf von Witting, Jörg Litschke and Johan Richter.