One stop clinic for assessment of risk for fetal anomalies: a report of the first year of prospective screening for chromosomal anomalies in the first trimester - Spencer, K; Spencer, C E; Power, M; Moakes, A; Nicolaides, K H (BJOG, 2000)
. Doi: 10.1111/j.1471-0528.2000.tb11619.x