Transthoracic Echocardiography Using Second Harmonic Imaging with Valsalva Manoeuvre for the Detection of Right to Left Shunts
Eur J Echocardiogr 5:176-181, Clarke,N.R.,et al, 2004
Transesophageal Echocardiography in Patients with Focal Cerebral Ischemia of Unknown Cause
Stroke 27:691-694, Rauh,G.,et al, 1996