Mike Benayoun, "Bulgaria: Pechani Yabalki", 196 flavors[1]
archive.org
"Black Caps par Excellence", Eliza Acton, Modern Cookery, in All Its Branches, 1845, p. 531
books.google.com
Twentieth Century Cook Book, an Up-to-date and Skillful Preparation on the Art of Cooking and Modern Candy Making Simplified, 1921, "Baked Apples with Dates", p. 105
denverpost.com
Dorrie Greenspan, "For pure coziness, nothing beats the soft sweetness of a baked apple", Denver Post, October 10, 2016
foodsofengland.co.uk
"Norfold Dried Biffins", The Foods of England Project[2]