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

https://www.forbes.com/sites/glennsolomon/2020/09/15/monetizing-open-source-business-models-that-generate-billions/?sh=5d649f3534fd

https://livablesoftware.com/study-open-source-foundations/

https://www.unicef.org/innovation/media/206/file/Open Source Business Model.pdf

https://fourweekmba.com/open-source-business-model/

https://hbswk.hbs.edu/item/the-organizational-model-for-open-source

https://dirkriehle.com/publications/2010-selected/the-economic-case-for-open-source-foundations/comment-page-1/

https://insights.blossomcap.com/successful-open-source-business-models-2709e831e38a