- Infant and Toddler Development and Responsive Program PlanningDonna S. Wittmer, Sandy Petersen
- Call of Cthulhu 7th Ed. QuickStartChaosium Inc, Sandy Petersen et al.
- Call of Cthulhu Rpg Keeper RulebookSandy Petersen, Lynn Willis et al.
- Petersen's field guide to Cthulhu monstersSandy Petersen
- S. Petersen's Field Guide to Lovecraftian HorrorsSandy Petersen, Lynn Willis et al.
- Infant and Toddler Development and Responsive Program PlanningDonna Wittmer, Sandy Petersen
- Cthulhu ClassicsScott Aniolowski, Sandy Petersen
- Call of CthulhuSandy Petersen, Lynn Willis
- Shadows of Yog-SothothSandy Petersen
- Petersen's field guideSandy Petersen
- Call of Cthulhu Keeper ScreenSandy Petersen, Mike Mason et al.
