Changes in neonatology: comparison of two cohorts of very preterm infants (gestational age <32 weeks): the Project on Preterm and Small for Gestational Age Infants 1983 and the Leiden Follow-Up Project on Prematurity 1996-1997 - Stoelhorst,G.M.; Rijken,M.; Martens,S.E. (Pediatrics, 2005)