1. Emergency and elective surgery in patients over age 70.;Keller;Am Surg,1987
2. Surgical care in octogenarians.;Bufalari;Br J Surg,1996
3. Outcomes of surgery in patients 90 years of age and older.;Hosking;JAMA,1989
4. Surgery in patients aged 80 years and over. A retrospective comparative study from 1981 and 1987.;Schoon;Eur J Surg,1991
5. Emergency surgical admissions in patients aged more than 80 years: a study over four decades.;Menon;Ann R Coll Surg Engl,2000