2000, Rebecca G. Stephenson & Linda J. O'Connor, Obstetric and Gynecologic Care in Physical Therapy, SLACK Incorporated (2000), ISBN 1556424159, page 53:It is more recently the opinion of specialists that psychogenic symptoms may be associated with some dysmenorrheic patients, but that these symptoms are not necessarily the cause of physical complaints.
2002, Ethel Sloan, Biology of Women, Delmar Thomson Learning (2002), ISBN 0766811425, page 99:In severely dysmenorrheic women, there is exaggerated uterine contractility and a significantly higher prostaglandin content in the menstrual blood with a twofold to tenfold increase when compared with women who do not have menstrual pain.
2012, Helen S. Driver, "Sleep and Gender: The Paradox of Sex and Sleep?", in The Oxford Handbook of Sleep and Sleep Disorders (eds. Charles M. Morin & Colin Espie), Oxford University Press (2012), ISBN 9780195376203, page 276:Baker and colleagues (1999) reported that dysmenorrheic women had reduced sleep efficiency when experiencing menstrual pain, with increased wakefulness, movement, and stage 1 sleep compared to pain-free phases of their cycle.
