1. Facial fractures. A review of 368 cases;Afzelius;Int. J. Oral Surg.,1980
2. Facial fractures in Umeå 1957–1974;Åstrand;Swed. Dent. J.,1976
3. Facial fractures in the hospital of Heisingborg 1977;Bende;Läkartidningen,1979
4. Facts and figures on motor-cycle accidents in 1974;Carraro,1975