1. Early follicular phase hormone levels in relation to patterns of alcohol, tobacco, and coffee use 
Jennifer Lucero, M.D., Bernard L Harlow, Ph.D., Robert L Barbieri, M.D., Patrick Sluss, Ph.D., Daniel W Cramer, M.D. 
Fertility and Sterility 
Volume 76, Issue 4, Pages (October 2001)
DOI: /S (01)

2. FIGURE 1
The effect of caffeine consumption on early follicular phase estradiol levels (log transformed) in women with low (<217.5 mg/d) and high (≥217.5 mg/d) cholesterol consumption.
Lucero. Early follicular phase E2 and caffeine. Fertil Steril 2001.
Fertility and Sterility  , DOI: ( /S (01) )