VenkataramanP.S., TsangR.C., SteichenJ.J., GreyI., NeylanM., FleischmanA.R.Early neonatal hypocalcemia in extremely preterm infants. High incidence, early onset, and refractoriness to supraphysiologic doses of calcitriol.Am J Dis Child.1986; 140(10): 1004–1008 Medline.
