Classes by Tanner Tolman on FamilySearch: https://www.familysearch.org/en/help/helpcenter/lessons/the-denmark-regional-series-bornholm-part-1-introduction
Link to Bornholm local and family history. Includes a database of births from 1815 to 1940.
Database of Church Records before 1814 for Bornholm.
Link to 1771 Census for Bornholm (widows and widowers) https://www.sa.dk/ao-soegesider/da/billedviser?bsid=474824#474824,84850248
Historisk-samfund-bornholm. Some digitized issues of Kirkehistorie Samlinger can be found on Haithi Trust: Hathi Trust
Midwife records for Bornholm can be found at this link: https://www.sa.dk/ao-soegesider/da/billedviser?epid=21009039#334666,67384160
See also this link: https://www.sa.dk/ao-soegesider/da/other/index-creator/140/807482/21009039
http://www.bornholm-stamtavle.dk/indexen.html [Website from Camilla Dahl]
Sonne Family History: https://slaegtsbibliotek.dk/911283.pdf
Bornholm on Wiki https://familysearch.org/wiki/en/Bornholm:_Military_L%C3%A6gd_Numbers_after_1870