The following sources were consulted in the preparation of the article “Why people once slept in two shifts instead of one.”
- Reflections on ‘Have we lost sleep?’
- Sleep We Have Lost: Pre-industrial Slumber in the British Isles
- The Modernization of Western Sleep: Or, Does Insomnia have a History?
- In short photoperiods, human sleep is biphasic
- Extended sleep in humans in 14 hour nights (LD 10:14): relationship between REM density and spontaneous awakening
- Segmented Sleep in Preindustrial Societies
- REM sleep complicates period adding bifurcations from monophasic to polyphasic sleep behavior in a sleep-wake regulatory network model for human sleep
- William Eastman. Damage damage other. 6th December 1769.
- The Proceedings of the Old Bailey. 7th July 1773.
