SPIEGEL K., LEPROULT R., VAN CAUTER E. Impact of a sleep debt on metabolic and endocrine function. Lancet, 354 (1999), 1435-1439.

SPIEGEL K., SHERIDAN J.F., VAN CAUTER E. Effect of sleep deprivation on response to immunization. JAMA, 288 (2002), 1471-1472.

SPIEGEL K., LEPROULT R., L'HERMITE-BALERIAUX M., COPINSCHI G., PENEV P., VAN CAUTER E. Leptin levels are dependent on sleep duration: relationships with sympathovagal balance, carbohydrate regulation, cortisol, and thyrotropin. J. Clin. Endocrinol. Metab., 89 (2004), 5762-71.

SPIEGEL K., TASALI E., PENEV P., VAN CAUTER E. Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of Internal Medicine, 141 (2004), 846-50.  

SPIEGEL K., Tasali E, Leproult R, VAN CAUTER E. Effects of poor and short sleep on glucose metabolism and obesity risk. Nature Reviews Endocrinology, 5 (2009): 253-261.