APA (7th ed.) Citation

Great Britain. Sovereign, Great Britain. Public Record Office, & Harvester Microform (Firm). Ancient correspondence.

Chicago Style (17th ed.) Citation

Great Britain. Sovereign, Great Britain. Public Record Office, and Harvester Microform (Firm). Ancient Correspondence.

MLA (8th ed.) Citation

Great Britain. Sovereign, et al. Ancient Correspondence.

Warning: These citations may not always be 100% accurate.