Start with high-confidence scandinavian history books, then narrow by subgenre or adjacent topics.
Orkneyinga Saga
Anonymous, Hermann Pálsson
The Opposite of Cold
Michael Nordskog
Ivory Vikings: the Mystery of the Most Famous Chessmen in the World and the Woman Who Made Them
Nancy Marie Brown
Northmen
John Haywood
The Real Valkyrie
The Northwomen
Heather Pringle
The Last Viking
Don Hollway
Children of Ash and Elm
Neil Price
Freyja
L. Dean Lee
Thor
Graeme Davis
The Wolf Age
Tore Skeie, Alison McCullough
