@article{f6e6b080410c46e582d1a9cfbf48db13,
title = "OP23.01: A prospective study evaluating the performance of first trimester combined screening for trisomy 21 using repeated sampling of the maternal serum markers PAPP-A and free β-hCG",
author = "Petersen, {Olav Bj{\o}rn}",
year = "2012",
doi = "10.1002/uog.11606",
language = "English",
volume = "40",
pages = "122--123",
journal = "Ultrasound in Obstetrics and Gynecology",
issn = "0960-7692",
publisher = "John/Wiley & Sons Ltd",
number = "S1",
note = "22th World Congress on Ultrasound in Obstetrics and Gynecology : ISUOG ; Conference date: 09-09-2012 Through 12-09-2012",
}