by Nagel, Hélène T. C, de Haan, Timo R, Vandenbussche, Frank P. H. A, Oepkes, Dick, Walther, Frans J
Published in Obstetrics and gynecology (New York. 1953) (01.01.2007)

by Lopriore, Enrico, Nagel, Helene T.C, Vandenbussche, Frank P.H.A, Walther, Frans J
Published in American journal of obstetrics and gynecology (01.11.2003)

by Nagel, Hélène T. C., Vandenbussche, Frank P. H. A., Keirse, Marc J. N. C., Oepkes, Dick, Oosterwijk, Jan C., Beverstock, Geoffrey, Kanhai, Humphrey H. H.
Published in Prenatal diagnosis (01.05.1998)