An Unashamed Defense of Coffee, Authors: Roseane M. Santos, Roseane M. Santos, M.Sc., Ph.D. & Darcy R. Lima, M.D., Ph.D., Darcy R. Lima, Xlibris Corporation publishers, 2009, [1], Retrieved Aug. 29, 2014, (see page 66), "...researchers found worked best was a Caffeine Nap..."
Mollicone, Daniel J.; Van Dongen, Hans P.A.; Dinges, David F. (2007). "Optimizing sleep/wake schedules in space: Sleep during chronic nocturnal sleep restriction with and without diurnal naps". Acta Astronautica. 60 (4–7): 354. Bibcode:2007AcAau..60..354M. doi:10.1016/j.actaastro.2006.09.022.
Reyner, L. A; Horne, J. A (1997). "Suppression of sleepiness in drivers: Combination of caffeine with a short nap". Psychophysiology. 34 (6): 721–5. doi:10.1111/j.1469-8986.1997.tb02148.x. PMID9401427.
Wan, J; Lau, E; Lee, T (2013). "The effect of caffeine nap on declarative and procedural memory in elderly". Sleep Medicine. 14: e309. doi:10.1016/j.sleep.2013.11.758.
Mollicone, Daniel J.; Van Dongen, Hans P.A.; Dinges, David F. (2007). "Optimizing sleep/wake schedules in space: Sleep during chronic nocturnal sleep restriction with and without diurnal naps". Acta Astronautica. 60 (4–7): 354. Bibcode:2007AcAau..60..354M. doi:10.1016/j.actaastro.2006.09.022.
Reyner, L. A; Horne, J. A (1997). "Suppression of sleepiness in drivers: Combination of caffeine with a short nap". Psychophysiology. 34 (6): 721–5. doi:10.1111/j.1469-8986.1997.tb02148.x. PMID9401427.
ANAHAD O'CONNOR OCTOBER 31, 2011, The New York Times, Really? The Claim: For a More Restful Nap, Avoid Caffeine, Retrieved Aug. 29, 2014, "...sleep researchers in England found that drinking a cup of coffee and then immediately taking a 15-minute nap was even more effective....
oprah.com
Corrie Pikul, 02/27/2012, Oprah magazine, 6 More Health Myths—Busted!, Retrieved Aug. 29, 2014, "...Drinking a cup of coffee and then immediately snoozing for 15 minutes was more effective at reviving a wiped-out person.."
prevention.com
The Editors of Prevention, Prevention magazine, 6 Good Health Habits Made Better, Retrieved Aug. 29, 2014, "...1. Take a "caffeine nap"..."
Naomi Imatome Yun, World Lifestyle, Get a Jolt with the “Caffeine Nap”, Retrieved Aug. 29, 2014, "Napuccino... Longborough University scientists have found out that having caffeine before a short nap boosts alertness...