The editors of the Journal of West African Languages (JWAL) have continued putting PDF versions of past articles on their web site. All articles published before 2002 are now available for free download at http://journalofwestafricanlanguages.org. Check out what is online for Chadic including Hausa.
Thanks for you people who work on Chadics. But many languages more particularly in Northern Cameroon and Central African Republic still need to be described.