The Canon EOS R is still a pretty incredible camera even years after its introduction. It's still more capable than many newer cameras.
DPReview: Canon EOS R vs Nikon Z 6 vs Sony a7 III, which is best?
What does the EOS R tell us about Canon and the RF mount's future?: Digital Photography Review
Canon EOS RP Mirrorless Camera Review
Canon R100 Review - Underwater Photography Guide
First Impressions: Canon EOS R kit, by Happy to Help
Review: Canon EOS R (The Mirrorless Camera That Truly Surprised Me)
Canon EOS R Mirrorless Digital Camera (Body Only) *USED*
Canon EOS R7 APS-C Mirrorless Camera
Why do so many people hate the Canon EOS R when it is as powerful or more so than the 5D MkIV? - Quora
Review: Canon EOS R (The Mirrorless Camera That Truly Surprised Me)
Canon EOS R Mirrorless Review for Weddings - Chris Giles Photography
Lens Rentals
We Review the Canon EOS R8 Mirrorless Full Frame Camera
Canon EOS R Review & Sample Image Files by Ken Rockwell
Review: Canon EOS R (The Mirrorless Camera That Truly Surprised Me)