Bibliography
- Marvel Encyclopedia Volume 6: Fantastic Four (November 2004)
- Official Handbook of the Marvel Universe: Alternate Universes 2005
- Marvel Legacy: The 1960s Handbook (2006)
- Marvel Legacy: The 1970s Handbook (2006)
- Marvel Legacy: The 1980s Handbook (2006)
- Marvel Legacy: The 1990s Handbook (2007)
Read more about this topic: Multiverse (Marvel Comics)