Daily variation in the concentration of melatonin and 5-methyoxytryptophol in the human pineal gland: effect of age and Alzheimer's disease. - Skene,D.J.; Vivien-Roels,B.; Sparks,D.L.; Hunsaker,J.C.; Pevet,P.; Ravid,D.; Swaab,D.F. (Brain Res, 1990)