Henneberg, M. and Kozak, J. 1976. Seasonal rythm of births in an rural XIXth century population: Parish of Szczepanowo (Bydgoszcz Voivodeship). Anthropological Review. 42, 1 (Jan. 1976), 19–31. DOI:https://doi.org/10.18778/1898-6773.42.1.02.