Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "Gal-walas." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 28.
, galwealas, nom. acc; gen. a; dat. um; pl. m. [wealh foreign; cf. Bryt-walas] Gauls, Frenchmen, people of Gaul in a body, and as the name of a people is often used where according to later usage the name of their country would be found, the word may be translated Gaul, France; Galli, Gallia :-- Hér wæs Brihtwald gehálgod to ærcebiscope fram Godune Galwala biscop in this year [A. D. 693] Brihtwald was consecrated archbishop by Godun bishop of the Gauls, Chr. 693; Erl. 43, 17. He gewát into Galwalum he went into Gaul, Chr.