1. Urinary follicle-stimulating hormone peak as a biomarker for estimating the day of ovulation 
Hongxia Li, M.D., Jiangang Chen, M.D., James W Overstreet, M.D., Ph.D., Steven T Nakajima, M.D., Bill L Lasley, Ph.D. 
Fertility and Sterility 
Volume 77, Issue 5, Pages (May 2002)
DOI: /S (02)

2. FIGURE 1
Frequency distributions in 20 menstrual cycles of the days of peak hormone concentrations and the DLTs as determined by two algorithms. The data are aligned to the day of follicular collapse (day 0) as determined by serial ultrasonography.
Li. Estimating the day of ovulation. Fertil Steril 2002.
Fertility and Sterility  , DOI: ( /S (02) )