I'm currently trying to learn more about the Lorentz- and Poincare Lie-algebras and the representation theory about them. But I'm really struggling with the material that we were given and I'm also having a hard time finding something suitable on the internet. Until now I've looked into:
- Notes on Quantum Mechanics, K. Shulten, Chapter 10.1
- Introduction to relativistic quantum field theory, R. Soldati, Chapters 1.2.6-1.2.8
- The Representation Theory of the Lorentz Group, Jackson Burzynski
Number  covers basically everything I need, but I'm having a hard time following his conclusions -- at the end of each section he just starts stating things as facts without giving any kind of explanation (for example, he mentions two dimensional left spinor Weyl representations, but doesn't explain anything about them). Number  was just to short, it didn't cover enough of the material needed and number  had a nice approach on deriving the Lie-algebra of the Lorentz-group but was, for me at least, not clear enough when talking about the representation theory (although a lot better than ). It obviously lacks the part about the Poincare group.
So what I'm looking for: Books, papers, etc. that explain how on can find the Lie-algebra of the above mentioned groups and show how we can find the representations which are used in QFT. I don't mind if the recommendation is repetitive or long, etc, as long as it explains these concepts well.