D20 System

Independently published

The Ultimate d20 RPG Systems: Create Your Own Tabletop Adventures: A Comprehensive Guide to World-Building, Character Creation, Magic Systems, and More

Ultraverse Roleplaying System (English Edition)  

Imprint unknown

Besm D20 Anime Role-Player's Handbook            

Guardians of Order

The D20 System Mecha Handbook                    

Fast Forward Entertainment Inc

The Encyclopedia of Demons & Devils: 2          

Descartes Editeur

L'appel de Cthulhu D20 System                    

Steve Jackson Games

Munchkin Player's Handbook                      

White Wolf Pub

The Divine and the Defeated                      

Brand: Green Ronin Publishing

The Advanced Gamemaster's Guide: An Advanced Rulebook for the D20 System

Sword & Sorcery Studio

Monte Cook's Arcana Unearthed: Dm's Screen and Player's Guide: A Game Accessory