Weglage, J., Wiedermann, D., Denecke, J., Feldmann, R., Koch, H.-G., Ullrich, K., et al. (2002). Individual blood-brain barrier phenylalanine transport in siblings with classical phenylketonuria. Journal of Inherited Metabolic Disease, 25(6), 431-436. doi:10.1023/A:1021234730512.