Birch
| Author(s) | Title | Reference | |
|---|---|---|---|
| O.S. Anderson | The place-names of Hertfordshire, by J. E. B. Gover, Allen Mawer, F. M. Stenton | 9/2, p. 88 | |
| F.E. Harmer | The Place-Names of Derbyshire (English Place-Names Society, vols. XXVII-XXIX), by Kenneth Cameron | 29/2, p. 142 |