1. P. Richmond, B.M. Roehner, Coupling between death spikes and birth troughs. Part 1: Evidence. Preprint LPTHE, UPMC, Paris, 2017.
2. Bureau of the Census, [various years, starting in 1915]: Birth Statistics. Government Printing Office, Washington DC.
3. Bureau of the Census, [various years]: Mortality Statistics. Government Printing Office, Washington DC.
4. H. Bunle, Le mouvement naturel de la population dans le monde de 1906 à 1936. [Vital statistics of many countries world-wide from 1906 to 1936.] Editions de l’Institut d’Etudes Démographiques, Paris, 1954.
5. Finland, The French subtitle of this official publication is: Éléments démographiques principaux de la Finlande pour les années 1750-1890, II: Mouvement de la population. The Finnish title is: Suomen [Finland] Väestötilastosta [demographical elements] vuosilta [years] 1750-1890, II: Väestön [population] muutokset [changes]. Helsinki, 1902. [Available online, 526 p.].