His lens tests are excellent. The lens rentals blog is the best place to find them [0]. If you're in market for high quality lenses, lens rental blog is a great resource.

I also like cameralabs' lens tests [1]. Not as scientific as lensrentals, however, it has real samples and images of charts for comparison, so you can get a sense for what the different resolution means in image resolution. It also tests things beyond resolution. Such as out of focus rendering, coma, sun stars, etc.

[0] https://www.lensrentals.com/blog [1] https://www.cameralabs.com/camera-lens-reviews/