A. J. Johnson Company, Johnson's universal cyclopedia: a new edition, pp. 336, 337, 338; 1895 D. Appleton and company & A. J. Johnson company
The Nordic Languages; 202. The typological development of the Nordic languages I: Phonology. 1. Proto-Nordic: 1853. 2. Common Nordic: 1855. 3. Old East Nordic: 1856, 1859. 4. Old West Nordic: 1859
M. Schulte. "Phonological developments from Old Nordic to Early Modern Nordic I: West Scandinavian." The Nordic languages vol. 2 pp. 1081–1096. Monophthongization: page 1082; /øy/: page 1082; Reduced vowels: page 1085
Orrin W. Robinson, Old English and Its Closest Relatives, pg. 83
