I admit that Creative Commons Zero makes no legal sense with #BGOffice's EN2BG/BG2EN dictionaries, but at the dict ludost mailing list no one objected against it back in 2020. It's just a declaration that I have no right to claim any kind of ownership. I rediscovered them when I logged back to my account. Still working fine with #ColorDict and #GoldenDict. Feel free to fork them because I am terrible at maintaining anything serious on GitHub:

https://github.com/cellfourteen/English-Bulgarian-dictionaries-in-StarDict-format