Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "yfel." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 752.
;adj. Evil, ill, bad :-- Yfel malus, Wrt. Voc. i. 74, 47. I. in a moral sense :-- Yfel mann of yfelum goldborde bringð yfel forð, Mt. Kmbl. 12, 35. Hié nǽnigo firen ne gewundode, ne yfel gewitnes (witness of wrong-doing) ne wrégde, Blickl. Homl. 161, 33. Ðæt ðǽr mæge yfelu uncyst on eardian, 37, 10. Se yfela déma onféhþ medmycclum feó, and onwendeþ ðone rihtan dóm, 61, 30. Se yfela þeów, Mt. Kmbl. 24, 48. Se yfela willa, Bt. 36, 7; Fox 184, 31. Se yfela unrihtwísa cynincg, Met. 15, 1. Fram yfelum menn ab homine malo, Ps. Th. 139, 1. Yflum, Exon. Th.