When authors refer to other great works, people, and events, it’s usually not accidental. Put on your super-sleuth hat and figure out why.
There aren't any recognizable shout-outs in Princess Academy because it's set in Danland, in a place and time that definitely don't exist in the real world. We could give a shout-out to The History of Danland or to some of Miri and Company's favorite quarry songs, but you wouldn't know about them anyway.