Hypothalamic Regulation of Cyclic Ovulation: Evidence That the Increase in Gonadotropin-Releasing Hormone Pulse Frequency during the Follicular Phase Reflects the Gradual Loss of the Restraining Effects of ProgesteroneChristopher R. McCartney, John C. Marshall, Melissa B. Gingrich et al.|The Journal of Clinical Endocrinology & Metabolism|2002Cited by 71