Cite the scanned version of the original dicionary like this:
Bosworth, Joseph. "efen-." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth. Ed. Thomas Northcote Toller. Oxford: Clarendon Press, 1898. 24.
;adv. Add: (1) with an adverb :-- Efen (em) swá feala totidem, Hpt. Gl. 493, 70. (2) with a numeral :-- Mid allra óðerra priósta bútan ðissum mæsseprióstum efen LX with just sixty other priests besides these (already named), Cht. Th. 72, 4. Hé wunode on his ágenum mynstre em feówertig geára, Hml. S. 6, 360. On þám frummynetslæge wǽron twá and sixtig penega, and on þǽm æftran em sixtig, 23, 480. v. following compounds with efen-.