Complex sentence: He won a tournament at Trollhättan 1925 (Swedish Chess Championship), took 3rd at Karlskrona 1932, and took 12th in Nordic Chess Championship at Copenhagen 1934 (Aron Nimzowitsch won).
Split into simpler sentences: He won a tournament at Trollhättan 1925 (Swedish Chess Championship). He played in Nordic Chess Championship at Copenhagen 1934 (Aron Nimzowitsch won).