-
Prenasal thickness in trisomy-21 fetuses at 16-24 weeks of gestation.
Persico N, Borenstein M, Molina F, Azumendi G, Nicolaides KH.
Ultrasound Obstet Gynecol 2008;32:751-4. -
The 11-14 week scan.
Nicolaides KH, Heath V, Liao AW.
Baillieres Best Pract Res Clin Obstet Gynaecol 2000;14:581-94.