Early identification of persistent trophoblastic disease with serum hCG concentration ratios
N. E. Van Trommel, H. Ngo Duc, L. F.A.G. Massuger, C. P.T. Schijf, C. G.J. Sweep, C. M.G. Thomas
International Journal of Gynecologic Cancer Feb 2008, 18 (2) 318-323; DOI: 10.1111/j.1525-1438.2007.00993.x