1. Classification of congenital clefts of lip and palate;Davies;JAMA,1922
2. The modified stripped Y, a systematic classification for cleft lip and palate;Elsahy;Cleft Palate J,1973
3. Documentation. Discussion by invitation;Fogh-Andersen,1966
4. The stripped Y;Kernahan;Plast. Reconstr. Surg.,1971
5. A new classification for cleft lip and cleft palate;Kernahan;Plast. Reconstr. Surg.,1958