Arkham Unveiled: Adventures and Background in the Home of Miskatonic University (Call of Cthulhu), by Morrison, Mark, Watts, Richard, Herber, Keith
Cthulhu Casebook: A Plethora of Plots and Adventures for Call of Cthulhu 1920s (Call of Cthulhu #3305), by Harmon, Mark,Hamblin, William,Barton, William A.
Cthulhu Now: Modern Adventures and Background for Call of Cthulhu Roleplaying/3307, by Petersen,Okamoto, Jeff,Herber, Keith,Corless, Peter,Barton, William A.
Dead Reckonings (Call of Cthulhu Roleplaying Game), by Watts, Richard,Kingrea, J. Todd,Ross, Kevin
Delta Green (Call of Cthulhu Horror Roleplaying, Modern), by John Tynes,Adam Scott Glancy,Dennis Detwiller
Petersen's Field Guide to Cthulhu Monsters: A Field Observer's Handbook of Preternatural Entities (Call of Cthulhu), by Sandy Petersen
S. Petersen's Field Guide to Creatures of the Dreamlands (Call of Cthulhu Horror Roleplaying), by Lynn Willis,Sandy Petersen