Touma, C., Fenzl, T., Ruschel, J., Palme, R., Holsboer, F., Kimura, M., et al. (2009). Rhythmicity in Mice Selected for Extremes in Stress Reactivity: Behavioural, Endocrine and Sleep Changes Resembling Endophenotypes of Major Depression. PLoS ONE, 4(1): doi: 10.1371/journal.pone.0004325.