I ask this because I'm currently stuyding History in my 2^(nd) semester and did run across this problem while researching the events around the death of Harald Hardrada and the fight of William of Normandy against Harald Godwinsson in 1066. I found only three books (1066. The Battle for the Crown of England by Joerg Peltzer, 1066. The Conquest of England by the Normans by Dominik Waßenhoven and 1066. The Year of the Three Battles by Frank McLynn) and consider this to be a bare-bones minimum, but since I do not want to rely on three - possibly very different - perspectives given by the writers, I'm searching for more sources. It'd be nice if the fine folks around here could recommend some literature so I'm not completely boxed out of this topic.
There is a truly vast literature on 1066 and its battles, and the books you've located to date are all fairly popular versions of events. I'd suggest you need something a little bit more academic.
An excellent undergraduate level survey text covering this period is:
David Carpenter The Struggle for Mastery: Britain, 1066-1284 (2004)
... and the historiographical issues and main perspectives on the conquest and why it happened the way it did are very ably dealt with, at the same sort of level, by the very highly regarded Marjorie Chibnall in her
The Debate on the Norman Conquest (Manchester, 1999)
Also solid, accessible and recommendable are the following:
David Bates William the Conqueror (1989)
Eric John ‘The End of Anglo-Saxon England’, in J. Campbell (ed.), The Anglo- Saxons (1982)
R. Allen Brown The Normans and the Norman Conquest (2nd edn, 1985)
M. K. Lawson The Battle of Hastings 1066 (Stroud, 2002) - available as a downloadable pdf here
Ann Williams The English and the Norman Conquest (Woodbridge, 1995)
I hope this helps. Good luck.