Complex sentence: Singer and Berens jointly wrote "The Story of My Dictatorship" (1893), advocating tax reform, and "Some Unrecognized Laws of Nature" (1897).
Split into simpler sentences: Singer and Berens jointly wrote "The Story of My Dictatorship" (1893), advocating tax reform. Later Singer and Berens collaborated on "Some Unrecognized Laws of Nature" (1897).