Immunonutrition for Prophylaxis of Postoperative Complications in Elective Surgery: A Systematic Review of Randomised, Controlled Clinical Trials - Waitzberg, DL; Saito, H; Plank, LD; Jamieson, GG; Jagannath, P; Hwang, TL; Mijares, JM; Schneider, H; Bihari, D (Aktuelle Ernährungsmedizin, 2004)