Amazon has had the whole series that you can buy as a set in the past.
The World in Ancient Times:
The Early Human World
The Ancient Near Eastern World
The Ancient Egyptian World
The Ancient South Asian World
The Ancient Chinese World
The Ancient Greek World
The Ancient Roman World
The Ancient American World
The World in Ancient Times: Primary Sources and Reference Volume
The Medieval and Early Modern World
The European World, 400-1450
The African and Middle Eastern World, 600-1500
The Asian World, 600-1500
An Age of Empires, 1200-1750
An Age of Voyages, 1350-1600
An Age of Science and Revolutions, 1600-1800
The Medieval and Early Modern World: Primary Sources & Reference Volume