Complex sentence: In an appendix to "The Early Asimov", the author lists the first sixty stories he wrote in the late 1930s and 1940s, and notes that eleven of them were never sold and were eventually lost.
Split into simpler sentences: In an appendix to "The Early Asimov", the author lists the first sixty stories he wrote in the late 1930s and 1940s. In the commentary throughout the book, he notes that eleven of those stories were never sold and were eventually lost.