In what year was the letter to the Galatians written?

I found conflicting sources on the internet: 1. The first source said the Letter to the Galatians was written between 52-55 AD. 2. The second source said it was written between 48-49 AD. Just comparing the dates did not interest me. When I see the relationship with the Jerusalem Council, it becomes more interesting. 1. The first source put the Jerusalem council before the writing of the Galatian letter. 2. The second source put the writing of the Galatian letter before the Jerusalem council. (To be honest, I myself prefer the second source for my own reason). But since I'm not an expert, I wonder at the different timing between two source? **Which source is correct ?**