dement and kleitman
1957
crick and mitchinson
1986
tucker
2006- napping in NREM improved on declarative memory task
little hans
1909
michel siffre
1962
stephen and zucker
1972
milgram
1963
wagner
2004- maths problems easier after sleeping
gais
2006- foreign works better retained after sleeping
mazza
2016- splitting study sessions with sleep
czeisler
1990
karni
1994