Szymankiewicz, M: Trends of morbidity of very, very low birth weight neonates in University Hospital in Poznan between 1997-1999 : 1st International Symposium on Perinatal and Neonatal Developmental Medicine. Very-Low-Birth Weight/Extremely Low-Birth Weigh Infant: Delivery and Initial Care. Prague, November 5-7, 2000. Abstrakt