Complex sentence: He had already been translating Old Norse for the American-Scandinavian Society before completing his doctorate; his translation of the "Prose Edda" by Snorri Sturluson appeared the same year as he was awarded the degree.
Split into simpler sentences: He had already been translating Old Norse for the American-Scandinavian Society before completing his doctorate. His translation of the "Prose Edda" by Snorri Sturluson appeared the same year as he was awarded the degree.