論文（英文）
Inadequacy of prostate-specific antigen doubling time estimates calculated using an ultrasensitive assay of prostate-specific antigen for biochemical failure after radical prostatectomy.
Shimizu F, Matsuyama Y, Tominaga T, Ohashi Y, and Fujime M. Inadequacy of prostate-specific antigen doubling time estimates calculated using an ultrasensitive assay of prostate-specific antigen for biochemical failure after radical prostatectomy. Urologia Internationalis 2007; 79: 356-360.