I would complement this bibliography with, the deal.ii library. Probably, if you are interested in functional analysis, error estimates ecc., this is not the right place for you. If you want to have an essential, but rigorous, mathematical picture, plus implementation strategy and software, well, there in no better place check than deal.ii tutorials.

Let me also add that Wolgangs's video lectures are a precious resource.

I would complement this bibliography with, the deal.ii library. Probably, if you are interested in functional analysis, error estimates etc., this is not the right place for you. If you want to have an essential, but rigorous, mathematical picture, plus implementation strategy and software, well, there is no better place to check than deal.ii tutorials.

Let me also add that Wolfgangs's video lectures are a precious resource.