Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "K." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 598.
THE letter k appears to have had no distinct duty to perform in the oldest English, but to have been a mere variant of c. In the MSS. (more particularly the Cotton) of Alfred's translation of Gregory's Pastoral Care, where in the words kyning, kyun &c. it occurs not unfrequently, this writing is not uniform. Thus in Sweet's edition Angelkynn is found p. 2, ll. 3, 13, but Angelcynn l. 4 ; whilst in each case the Hatton MS. has c. So in the following page in l. 10, kynn, in l. 20, cynn. On pp. 2, 3, l.