Study protocol: baby-OSCAR trial: Outcome after Selective early treatment for Closure of patent ductus ARteriosus in preterm babies, a multicentre, masked, randomised placebo-contr... -н Gupta, S, Juszczak, E, Hardy, P, Subhedar, N, Wyllie, J, Kelsall, W, Sinha, S, Johnson, S, Roberts, T, Hutchison, E, Pepperell, J, Linsell, L, Bell, JL, Stanbury, K, Laube, M, Edwards, C, Field, D, ‘The Baby-OSCAR Collaborative Group’