British Archaeological Association
Cambridgeshire Historic Churches Trust
Castor Church Trust Facebook page
Castor entry in the Corpus of Romanesque Sculpture in Britain
Middle Nene Archaeological Group
Nene Valley Archaeological Trust
Peterborough Decorative & Fine Arts Society
St Remigius Church, Waternewton
Stephen Upex at Cambridge University
Stibbington Centre – residential
Stibbington Centre -day visits