If you are looking for a physical "paper" book, there are two primary official Japanese publications:
: You can find translated lists of Skills and Traits on platforms like Scribd, which describe the effects of various abilities like "Crafty Sapper" or "Critical". Dragon Quest Monsters: Joker 3 Professional [De...
Since no official English paper manual exists, the community has created comprehensive digital "papers" and spreadsheets to translate the game's complex systems: If you are looking for a physical "paper"
: A specialized guidebook focusing on the game's world and mechanics, often found on secondary markets like eBay . Digital Reference Guides (English) Dragon Quest Monsters: Joker 3 Professional [De...
: A detailed Google Sheets Document created by fans lists every synthesis formula and monster habitat specifically for the Professional version.