The paper:

https://www.pnas.org/doi/10.1073/pnas.070039597

https://www.ucl.ac.uk/news/2022/feb/london-taxi-drivers-brains-being-scanned-alzheimers-research#:~:text=Previous%20studies%20have%20shown%20that,confusion%20associated%20with%20the%20disease.

That's the article which has a link to the source paper at the bottom.

And the actual paper: https://www.pnas.org/doi/10.1073/pnas.070039597

Saw a study recently that showed London cab drivers have enlarged hippocampus due to memorising the streets of London