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\bibitem{Hengartner_etal2017} M. P. Hengartner, T. H. C. Kruger, K. Geraedts, E. Tronci, T. Mancini, F. Ille, M. Egli, S. R{\~A}{\textparagraph}blitz, R. Ehrig, L. Saleh et al. "Negative affect is unrelated to fluctuations in hormone levels across the menstrual cycle: Evidence from a multisite observational study across two successive cycles." \textit{Journal of Psychosomatic Research} 99 (2017): 21--27. DOI: 10.1016/j.jpsychores.2017.05.018.

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