Lowell of Age of Ravens has been reviewing the GAZ series of gazetteers for the Known World/Mystara.
I always liked this series, especially how each one focused on a single region and how much the regions varied.
- GAZ 1: The Grand Duchy of Karameikos
- GAZ 2: The Emirates of Ylaraum
- GAZ 3: The Principalities of Glantri
- GAZ 4: The Kingdom of Ierendi
- GAZ 5: The Elves of Alfheim
- GAZ 6: The Dwarves of Rockhome
- GAZ 7: The Northern Reaches
- GAZ 8: The Five Shires
- GAZ 9: The Minrothad Guilds
- GAZ 10: The Orcs of Thar
- GAZ 11: The Republic of Darokin
- GAZ 12: The Golden Khan of Ethengar
- GAZ 13: The Shadow Elves
- GAZ 14: The Atruaghin Clans
- Dawn of the Emperors: Thyatis and Alphatia
- Gazetteers of Mystara: The Review List