| Reference | Reference code |
|---|---|
| European Demographic Observatory (ODE). Data collection submitted to the HFC by Jean-Paul Sardon, 2011. | BGR_01 |
| Human Fertility Database. Max Planck Institute for Demographic Research (Germany) and Vienna Institute of Demography (Austria). Available at www.humanfertility.org. Data downloaded on 02.08.2023. [Original URL] | BGR_03 |
| National Institute of Demographic Studies (INED) (1991). Population (French Edition) 46e(3): 703-768. Data downloaded on 25.07.2014. [Original URL] | BGR_02 |