"The Easy Pressure Cooker Cookbook" by Diane Phillips and "Miss Vickie's Big Book of Pressure Cooker Recipes" by Vickie Smith are both good pressure cooker cookbooks. Both books offer over 400 recipes.
The recipes in "The Easy Pressure Cooker Cookbook" include complete meals, stocks, sauces and desserts. The book also provides instructions regarding how to use a pressure cooker safely. "Miss Vickie's Big Book of Pressure Cooker Recipes" includes detailed instructions for recipes like one-pot meals, soups and desserts. The book also includes a buyer's guide to modern pressure cookers, cooking safely and cooking techniques that range from basic to advanced.