John Burke, John Bernard Burke: Encyclopædia of Heraldry or General Armory of England, Scotland and Ireland. Henry G. Bohn, London 1851, S. 246 (archive.org).
CROCKER, Sir John (1445–1508), of Lineham. In: Josiah C. Wedgwood, Anne Holt: History of Parliament 1439–1509. HMSO, London 1936, S. 236 (archive.org).
Daniel Lysons, Samuel Lysons: Magna Britannia. Band 6: Devonshire. Thomas Cadell, London 1822, S. 577 (archive.org).
CROCKER, Sir John, Knight. In: John Prince: The Worthies of Devon. Rees & Curtis, London 1810, S. 270–273 (archive.org).
