Hi, I'm currently in my last year of undergraduate degree, I have a basic knowledge of GR (A. Zee) but I have a very limited knowledge of cosmology, I did not cover the cosmology portion of Zee's book as it is too superficial and I don't want to waste my time reading that. I think my time will be better off at reading proper cosmology books. Based on my searches, Cosmology by Harrison is a good starter but is it an undergrad book or too easy in that respect? Is Cosmology by Roos good for undergrad? For grad school Dodelson? Can anybody guide me on the proper outline of books for cosmology?