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\bibitem{Hjalgrim_etal2003} Hjalgrim, L. L., Westergaard, T., Rostgaard, K., Schmiegelow, K., Melbye, M., Hjalgrim, H., et al. (2003). Birth weight as a risk factor for childhood leukemia: a meta-analysis of 18 epidemiologic studies. \textit{Am J Epidemiol}, \textit{158}(8), 724--735.

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