1. Campbell, A. 1959. Old English Grammar. Oxford.
2. Chatman, S. 1958. The a/ae Opposition in OE. Word 14.
3. Dobson, E. J. 1962. Middle-English Lengthening in Open Syllables. TPhS, 124-148.
4. OE Vowel Lengthening and Vowel Shortening Before Consonant Groups;Eliason;SPh,1948