When using the biographical entries in this website you may come across references to the Oxford Dictionary of National Biography, Ancestry.co.uk (or Ancestry.com), Find My Past or ScotlandsPeople. These sites require subscriptions or payment so clicking on links to them usually produce a page restricting access unless you log in.
Oxford Dictionary of National Biography
If you want to use this and do not have access via an educational institution such as a university you can get access in the United Kingdom at a public library. Go to ODNB Public Library access for more details about this.
Find My Past.
Though you can do initial searches for free, the details of all the records have to be paid for.