The Good Housewife's Jewel, Thomas Dawson
To The King's Taste, Lorna Sass
The Medieval Cookbook, Maggie Black
Platina's On Right Pleasure and Good Health, Mary Ella Milham, Pegasus Press
The Neapolitan Collection, Terrence Scully
The Forme of Cury, Samuel Pegge
The Opera of Bartolomeo Scappi (1570), Terrence Scully
Turkey Legs and Scotch Eggs, International Wenches Guild Local 24, This is a cookbook put together by a group of people for a fundraiser. The end section has "medieval" recipes and those I have used that have sources I have hunted down.
To The Queen's Taste, Lorna Sass
Ouveture de Cuisine 1604 Master Lancelot de Casteau Montios PDF (French)
Libre del Coch 1529 Ruperto de Nola PDF (Spanish)
Libro di Cucina/ Libro per Cuoco 14th/15th century Anonimo Veneziano Translated by Helwyse de Birkstead PDF (Italian)
Koge Bog 1616 Salomone Sartorio PDF (Danish)
I also source great deal of stuff from online when I can in order to properly document things.