- CollectionCamb. Medieval History - Papers relating to the Cambridge Medieval History Series
- SeriesBox 1-2 - Letters to and from contributing historians to Cambridge Medieval History
- SubseriesBox 1 - Letters relating to historians A-L
- File29 - Letters to and from C. J. B. Gaskoin
- Item1 - Autograph card, signed, to J. R. Tanner from C. J. B. Gaskoin
- Item2 - Copy of notes made by J. R. Tanner