1. L. A. Althemus, The incidence of cleft lip and palate among North American Negros., Cleft Palate J, 1966 .3 :357 –361 .
2. B. Antoszewski, and J. Kruk-Jeromin .Epidemiology of cleft lip and palate in Lodz, Poland, in the years 1981–1995., Acta Chir Plast, 1997 .39(4) :109 –112 .
3. B. Azaz, and K. E. Koyoumdjisky .Incidence of clefts in Israel., Cleft Palate J, 1967 .4 :227 –233 .
4. P. A. Baird, A. D. Sadovnick, and I. M. Yee .Maternal age and oral cleft malformations: data from a population-based series of 576815 consecutive livebirths., Teratology, 1994 .49 :448 –451 .
5. C. Ballew, High prevalence of the cleft lip among the Bari Indians of the Western Venezuela., Cleft Palate Craniofac J, 1993 .30 :411 –413 .