Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "neom." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 649.
, neam, nam = ne eom am not, nis = ne is is not :-- Ðæs gescý neom (nam, Lind.: næm, Rush.) ic wyrðe tó berenne, Mt. Kmbl. 3, 11. Neam ic non sum, Ps. Surt. 118, 30. Sí eówer sprǽc: Hyt ys, hyt ys;nyt nys, hyt nys, Mt. Kmbl. 5, 37. Nis álýfed it is not allowed, Homl. Th. i. 94. 29.