Katherine Stephanie Benedicta Keats-Rohan, an Oxford history researcher, has written a brief biography of Alan for the Oxford Dictionary of National Biography. This article is available here:
http://www.oxforddnb.com/templates/article.jsp?articleid=52358&back=
A most interesting source of scholarly information about Alan and his times in England and neighbouring countries is:
Domesday People: A Prosopography of Persons Occurring in English Documents 1066-1166, Volume I: Domesday Book, by K.S.B. Keats-Rohan; published January 21, 1999; ISBN-10: 085115722X; ISBN-13: 978-0851157221.
Volume II of that work concerns Domesday Descendants. In 2011 Keats-Rohan followed up Volume I with an article that can be viewed online or downloaded as a PDF (if you have a Facebook account) from Academia dot Edu:
http://www.academia.edu/2039901/Domesday_People_Revisted
Primary sources for Alan's activities include charters of England and Brittany, and of course the Domesday Book, which is available online in various forms, of which my favourite is at:
The Wikipedia article is quite instructive, even though it contains some interpolation and interpretation of Alan's life by Yours Truly:
http://en.wikipedia.org/wiki/Alan_Rufus
Many comments of mine about this remarkable fellow are found in these blogs:
http://mercedesrochelle.com/wordpress/?p=239&cpage=1#comments
http://www.goodreads.com/group/105526-ask-carol-mcgrath/comments/22003639
I intend to add further information about Count Alan Rufus to this blog. So stay tuned.
Zoe