Richardus JH, Graafmans WC, Verloove-Vanhorick SP, Mackenbach JP (January 1998). "The perinatal mortality rate as an indicator of quality of care in international comparisons". Medical Care. 36 (1): 54–66. doi:10.1097/00005650-199801000-00007. PMID9431331.
Richardus JH, Graafmans WC, Verloove-Vanhorick SP, Mackenbach JP (January 1998). "The perinatal mortality rate as an indicator of quality of care in international comparisons". Medical Care. 36 (1): 54–66. doi:10.1097/00005650-199801000-00007. PMID9431331.