input: [Existing source reference] "The study's finding that the start-time effects are pronounced beginning at age 13 is consistent with the theory that hormonal changes in adolescence (typically beginning at 13 or 14) make it difficult for students to get enough sleep when school starts early, leading to sleep deficiencies that many studies have found to be associated with a decrease in cognitive performance." "School Start Times Found to Affect Student Achievement," by Finley Edwards, Education Next, May 3, 2012
output: "Our findings are consistent with the theory that hormonal changes in adolescence (typically beginning at 13 or 14) make it difficult for students to get enough sleep when school starts early,leading to sleep deficiencies that many studies have found to be associated with a decrease in cognitive performance."