S11	S8 AND S9 AND S10
S10	S6 OR S7
S9	S4 OR S5
S8	S1 OR S2 OR S3
S7	((start* adj3 tim*) OR (late* adj3 start*) OR (earl* adj3 start*) OR (delay* adj3 start*) OR (delay* adj3 time*) OR (stagger* adj3 start*) OR (stagger* adj3 tim*) OR (split* adj3 shift*) OR (double adj3 session*) OR (start* adj2 school*) OR (tim* adj2 school*) OR (time* adj3 day) OR (begin* adj3 day) OR (start* adj3 day) OR ((double* OR morning OR afternoon OR evening OR different) adj3 shift*) OR (tim* adj3 learn*) OR ((earl* or late* or school*) adj3 schedul*) OR Wakefulness OR sleep OR chronobiology OR "human biological rhythm" OR "human biological rhythms" OR circadian OR "phase shift")
S6	(MH "Wakefulness")
S5	("high school education" OR "secondary education" OR "secondary school" OR "junior high school" OR "middle school" OR "senior high school" OR "high school")
S4	(MH "Schools, Secondary")
S3	(adolescent OR Students OR teen* OR adolescent* OR "high school students" OR "young person" OR "young people" OR youth*)
S2	(MH "Students, High School")
S1	(MH adolescence)