1. Howlett History
http://www.photohistories.com/Photo-Histories/51/robert-howlett-and-the-power-of-photography

2.J P Mayall 1839-1906
http://www.racollection.org.uk/ixbin/indexplus?_IXACTION_=file&_IXFILE_=templates/full/person.html&person=16585