Copyright-free tactics collections

[lukasmonk]

I'm looking for copyright-free tactics collections to create training modules in Lucas Chess. Does anyone know of any good, free tactics collections? I'd like to find collections that have good, practical problems, but also complete solutions, so the learner can understand the point of the example.


If you know of any good collections, where the author will allow me to publish their collection (in Lucas Chess training modules), please let me know the URL.

Cheers
Lucas