Complex sentence: He specialized in shorter works like novellas and one-act plays, and in short stories like "The Green Tie" ("Die grüne Krawatte") he showed himself to be one of the early masters of microfiction.
Split into simpler sentences: He specialized in shorter works like novellas and one-act plays. And in his short stories like "The Green Tie" ("Die grüne Krawatte") showed himself to be one of the early masters of microfiction.