1. As far as I am concerned
2. as I know
3. to the best of my knowledge
I answered to the best of my knowledge
He didn’t do this to the best of my knowledge.
4. as far as I can make out
Anglais mot "z tego co mi wiadomo"(as far as I can make out) se produit dans des ensembles:
the red-headed 35. as far as i can tell