* Time perception research at the University of Manchester* "A Cognitive Model of Retrospective Duration Estimations", Hee-Kyung Ahn, et al., March 7, 2006.
== External links ==* Age perception calculator* Time perception research at the University of Manchester* Time Sense: Polychronicity and Monochronicity* "A Cognitive Model of Retrospective Duration Estimations", Hee-Kyung Ahn, et al., March 7, 2006.