"Quadripartite" adventure module in Dungeon Magazine #99

 (D&D 3E, Paizo Publishing)

Secrets of Los Angeles: A 1920s Sourcebook to the City of Angels

(Call of Cthulhu, Chaosium)

The Five Families: Criminal Organizations for Every Campaign World

 (Pathfinder, Adamant Entertainment)

That Sinking Feeling

 (D&D 5E, DM's Guild)

100 Quests

(D&D 5E, DM's Guild)

100 More Quests

(D&D 5E, DM's Guild)

College of Ventosity: A Bardic Tradition of Mastering the Flatulent Arts

(D&D 5E, DM's Guild)