Cite the scanned version of the original dicionary like this:
Bosworth, Joseph. "ac." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth. Ed. Thomas Northcote Toller. Oxford: Clarendon Press, 1898. 4.
.Take here the passage given under ǽc and add: dat. ǽc (ác) ; pl. ǽc :-- Aac robor, arbor (in the Corpus Glossary this is followed by 'robor, virtus, rubor color est,' ed. Hessels. p. 103: this may suggest an explanation for the earlier gloss aac color, Txts. 53, 535, which is copied in Wrt. Voc. ii. 14, 75), Txts. 93, 1749. Ác, Wrt. Voc. i. 285, 28: quercus vel ilex, 79, 73. Iung ác robur, 32, 28. Tó ðǽre gemearcodan ǽc, Cht. E. 355, 20. On thá radeludan ác; of ðǽre radeludan ǽc, C. D. B. iii. 44, 21.