第230篇The Classic Mayan Collapse

第262篇Language as a Historical Source

第294篇Polar Dinosaurs

第325篇Megafauna Extinctions in Ancient Australia

第358篇Birds and Food Shortage

第391篇Lunar History

第423篇Writing History

第455篇Geographic Isolation of Species

第498篇Representative Government in Colonial North America

第530篇Europe's Early Sea Trade with Asia