Creaciones
| ▲Título▼ | ▲C▼ | ▲Año▽ | ▲V▼ | ▲Concepto▼ |
|---|
| Lost Worlds of the Old West (junto a Kevin Ross y Todd A. Woods) |   | 2017 | — | Escritor |
| Proof of Life (junto a Jason C. Eckhardt) |  | 2009 | — | Escritor |
| Deities of the Mythos ("Malleus Monstrorum") (junto a Phil Anderson, Marion Anderson, Scott David Aniolowski et al.) | | 2006 | — | Escritor |
| Creatures of the Mythos ("Malleus Monstrorum") (junto a Marion Anderson, Scott David Aniolowski, Bruce Ballon et al.) | | 2006 | — | Escritor |
| Introductions ("Worlds of Cthulhu Issue #01") (junto a Adam Crossingham y Frank Heller) | | 2004 | — | Escritor |
| Introduction (to "H.P. Lovecraft's Dunwich") (junto a John T. Snyder) | ? | 2002 | — | Escritor |
| Languages and Scripts (junto a Dan Harms) |   | 2000 | — | Escritor |
| A Brief History of the Written Word (junto a Dan Harms y Kevin Ross) |  | 2000 | — | Escritor |
| Magic (junto a Janice Engan, Kevin Ross y Brian Sammons) |  | 1998 | — | Escritor |
| Deities of the Mythos ("The Creature Companion") (junto a Phil Anderson, Marion Anderson, Scott David Aniolowski et al.) | | 1998 | — | Escritor |
| Creatures of the Mythos ("The Creature Companion") (junto a Scott David Aniolowski, Shannon Appelcline, Bill Barton et al.) | | 1998 | — | Escritor |
| Arkham, a Summary |  | 1998 | — | Escritor |
| Gods of the Dreamlands (junto a K.L. Campbell-Robson, Sandy Petersen y Chris Williams) | | 1997 | — | Escritor |
| The Dreamlands Bestiary (junto a Scott David Aniolowski, K.L. Campbell-Robson, Larry DiTillio et al.) | | 1997 | — | Escritor |
| Creatures of the Mythos ("Ye Booke of Monstres II") (junto a Phil Anderson, Marion Anderson, Bill Barton et al.) | | 1995 | — | Escritor |
| Skills for the 1920s | | 1994 | — | Escritor |
| The Professional Investigator (junto a Gary O'Connell y Greg Rucka) | | 1994 | — | Escritor |
| Creatures of the Mythos ("Ye Booke of Monstres") (junto a Scott David Aniolowski, Fred Behrendt, John Carnahan et al.) | | 1994 | — | Escritor |
| On Becoming an Investigator (junto a Kevin Ross) | | 1994 | — | Escritor |
| 1920s Forensic Arts (junto a Gary O'Connell) | | 1994 | — | Escritor |
| Transport & Travel (junto a John Crowe III) | | 1993 | — | Escritor |
| Secret Cults (junto a Lucya Szachnowski) | | 1993 | — | Escritor |
| The Roaring Twenties (junto a Anne Merritt) | | 1993 | 9.00 | Escritor |
| Research & Resources (junto a Kenneth Faig Jr., Paul McConnell, Lucya Szachnowski y Justin Tynes) | | 1993 | — | Escritor |
| Mysterious Places | | 1993 | — | Escritor |
