Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "ǽc." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 9.
, e; f. An oak; quercus :-- Of ðære ǽce [MS. ǽc] andlang heges to ðæm wege from the oak and along the hedge to the road, Kmbl. Cod. Dipl. iii. p. 78, 7. v. ác.