Art and architecture books tend to only cite the works that alter the course of the field a degree or two. That also provides both the author and a reader with a narrative with which to chart the history of the subject.

For example almost no book cites the Guardian or Penobscot, but they almost always cite Saarinen's unbuilt Chicago Tribune design because so many buildings followed its style. While I love the Guardian, it's just a lavish example of a style, but not a trendsetter.