Are references with indication of page number uncommon in computer science?
Specifying which part of a long book or article you are referring to in your citation is a sound practice, but in general section, theorem or equation numbers are more common than page numbers for this task: [52, Section 3.5] or [52, Equation 3.23] rather than [52, Page 132-134].

Personally I use page numbers only as a last resource where nothing else is available: that is, when the section or equation I want to refer to does not have a number of its own.

I do not have a compelling reason for this, if not that section numbers are more robust to minor pagination changes, but this is the behaviour that I have seen more commonly.