Referencing cited authors
It is a bit easier on the reader if you say, instead:


  to enable personalized Web searches was first proposed by Smith in [32], however in [9] Jones, et al., showed this to be computationally inefficient. And Lindqvist in [33] iterated upon the method and made it suitable for real-time use....


It is easier, I suggest, for the reader to have something like a "picture" associated with a name, rather than just a reference number. And if the same author wrote more than one of the papers it brings them together in the reader's mind.