Complex sentence: Scott Warren Siegel (born 1951) is a US writer of mostly young adult shared universe science-fiction and fantasy, generally with his wife Barbara Siegel; many of their novels were published in the 1980s and 1990s.
Split into simpler sentences: Scott Warren Siegel (born 1951) is a US writer of mostly young adult shared universe science-fiction and fantasy, generally with his wife Barbara Siegel. Many of their novels were published in the 1980s and 1990s.