olemus
https://www.nato.int/cps/en/natohq/topics_156338.htm :
Hybrid threats combine military and non-military as well as covert and overt means, including disinformation, cyber attacks, economic pressure, deployment of irregular armed groups and use of regular forces. Hybrid methods are used to blur the lines between war and peace, and attempt to sow doubt in the minds of target populations. They aim to destabilise and undermine societies.

ülevaateid
https://www.dsn.gob.es/sites/dsn/files/EPRS_ATA%282015%29564355_EN.pdf

https://www.hybridcoe.fi/hybrid-threats-as-a-phenomenon/

https://www.studentsummit.cz/wp-content/uploads/2019/02/PSS-Hybrid-Threats-NATO.pdf

https://digiriiul.sisekaitse.ee/bitstream/handle/123456789/2576/2020%2010%20Sisejulgeoleku%20h%C3%BCbriidohtude%20tutvustamine%20ENG%20A4_web.pdf?sequence=1&isAllowed=y

https://en.wikipedia.org/wiki/Hybrid_warfare

https://www.govinfo.gov/content/pkg/GOVPUB-D101-PURL-gpo122539/pdf/GOVPUB-D101-PURL-gpo122539.pdf

https://euhybnet.eu/wp-content/uploads/2021/06/Conceptual-Framework-Hybrid-Threats-HCoE-JRC.pdf

https://www.astrid-online.it/static/upload/6902/69022a83cf93332b12ea00e69f331c8c.pdf

https://ccdcoe.org/incyder-articles/eu-policy-on-fighting-hybrid-threats/

https://www.baltdefcol.org/files/files/publications/Hybrid%20Threats_LIIA.pdf