Complete versions of several William stories can be found online at Project Gutenberg, ebooks and probably other copyright-free online libraries:
https://archive.org/stream/justwilliam34414gut/34414-8.txt
http://www.ebooksread.com/authors-eng/richmal-crompton/william-ala.shtml
Audio and TV versions can be found on YouTube, for example: https://www.youtube.com/watch?v=oy7MNkKO–4
and https://www.youtube.com/watch?v=kI1YWu2OVeE.
The story of Marvel’s failed William comic can be found at http://downthetubes.net/?p=27842.
The Just William Society is at: http://www.justwilliamsociety.co.uk/index.htm.
Other fan materials can be found via this fan site: http://www.justwilliam.co.uk/
References
[Anon] (2013) ‘Just William deserves critical recognition’, Times Higher, September 19th
Cadogan, Mary (1986) Richmal Crompton: The Woman Behind William. London: Allen and Unwin
Cadogan, Mary (2006) ‘Multimedia William’, in Fiona Collins and Jeremy Ridgman (eds.) Turning the Page. Children’s Literature in Performance and the Media New York: Peter Lang
Chambers, Aiden (1977) ‘The reader in the book: notes from work in progress’, Signal 23: 64-87
Greenway, Betty (2002) ‘William forever: Richmal Crompton’s unusual achievement’, The Lion and the Unicorn 26(1), 98-111
McVeigh, Jane (2016) ‘Fans of the archive: reading fan letters in Richmal Crompton’s archive’, European Journal of Life Writing vol. 5
Schwarz, Bill (1998) ‘Politics and rhetoric in the age of mass culture’, History Workshop Journal 46, 129-159
Simons, Chaim (2006) ‘Richmal Crompton’s “Just William” and the Jews’, http://reocities.com/CapitolHill/senate/7854/justwilliam.html
Stewart, Ralph (1988) ‘William Brown’s world’, Children’s Literature Association Quarterly, 13(4), 181-185
Whyte, William (2011) ‘Just William? Richmal Crompton and Conservative fiction’, in Clare Griffiths, James Nott and William Whyte (eds.) Classes, Cultures and Politics: Essays for Ross McKibbin Oxford: Oxford University Press
David Buckingham 