Blu-ray vs 4K: A Comprehensive Comparison

Blu-ray and 4K are totally different concepts but when used in DVDs they can be compared together.

Best 4K Blu-rays - CNET

Movies optimized for 4K versus full 4K Ultra HD: what's the difference?

Why owning a 4K Blu-ray player is both smart and stupid

DVD Exotica: 2001: An HD Odyssey

4K Blu-ray vs streaming

Archimago's Musings: 1080P Blu-Ray vs. 4K UHD Blu-Ray: The Prestige - Modern 35mm Filmmaking

Why do 1080p Blu-rays look better on a non-4k TV than a 4k Blu-ray disc? - Quora

HDR vs. 4K: What's the Difference?

4K UHD vs Blu-ray: How Do They Compare? - History-Computer