Takeuchi Hitomi, Nakao Mizuka, Kurose Wataru, Kawada Takahiro, Noji Teruki, Nakade Miyo, Tsuji Fujiko, Krejci Mirada, Harada Tetsuo, Intervention Study to Improve Meal Habit, Sleep Habit, Circadian Typology And School Marks in Japanese Elementary School Students, Journal of Sleep and Sleep Disorder Research, Volume 1, Issue 1, 2015, Pages 42-54, ISSN 2574-4518, https://doi.org/10.14302/issn.2574-4518.jsdr-16-1413. (https://openaccesspub.orgjsdr/article/516) Keywords: academic achievement mark; sleep habits; circadian typology; elementary school students; critical hours of 9 hours for better mark