1. Serum pattern of circulating free leptin, bound leptin, and soluble leptin receptor in the physiological menstrual cycle 
Franz Geisthövel, M.D., Nicoline Jochmann, M.D., Adji Widjaja, M.D., Rüdiger Horn, B.Sc., Georg Brabant, M.D. 
Fertility and Sterility 
Volume 81, Issue 2, Pages (February 2004)
DOI: /j.fertnstert

2. FIGURE 1
Median (solid line) and 95% confidence intervals (dashed lines) of circulating LH (A), E2 (B), P (C), and fL (D) during three consecutive physiological menstrual cycles. Days of cycle: M 1, the first day of menstruation; LHp 0, day of the peak of circulating LH; M−10/M−6 of the first cycle are equivalent to LHp +4/+8 of the second cycle; * vs. **: M−6/LHp+8 vs. M+4; P<.001.
Geisthövel. Circacyclic fluctuations of free leptin.Fertil Steril 2004.
Fertility and Sterility  , DOI: ( /j.fertnstert )