1. Altenglische Grammatik
2. Campbell, A. Old english grammar. Clarendon Press Oxford, 1959.
3. Campbell, A. An Anglo-Saxon dictionary based on the manuscript collections of joseph bosworth, enlarged addenda and corrigenda to the supplement by T. Northcote toller. Clarendon Press Oxford, 1972.
4. Cook, Albert S. The old english elene, phoenix, and physiologus. New Haven Yale University Press, 1919.
5. PIE *Duṷo ‘2’ in Germanic and Celtic, and the Nom.-Acc. dual of Non-Neuter o-Stems;Cowgill Warren.;Münchener Studien Zur Sprachwissenschaft,1985