Wongsiridej, P. , Ngerncham, S. , Usaha, S. , Chandranipapongse, W. , Tim R. Cressey and Bowornkitiwong, W. 2021. Serum Theophylline Concentrations in very Preterm Neonates Receiving Intravenous Aminophylline for Apnea. Siriraj Medical Journal. 73, 8 (Aug. 2021), 526–531. DOI:https://doi.org/10.33192/Smj.2021.68.