I believe "cross reference" is a term that is not typically applied to the study of literature. Allusions, as the above post points out, are literary references within a text - but these are not academic references cited to support an argument, claim or thesis. The above post does a good job of describing the concept of allusions.
Perhaps you are looking for examples of academic references though? These are made directly in a piece of academic writing as examples, evidence, and as contextualizing sources.
For instance, I might write an essay on Romeo and Juliet. In this essay, I want to write a few paragraphs about William Shakespeare's biography. To do this I will refer to a biographical text written on Shakepeare's life. Mentioning information that I have taken from another text (not Romeo & Juliet) can be called making a reference.
(In my understanding, cross referencing is a method of double-checking facts by finding mulitple corroborating sources and is a type of "investigative technique" more than an academic technique applied to literature.)
One cross-reference is an allusion. An allusion is a reference to another literary work. Allusions to the Bible are very common, but so are allusions to Greek and Roman myths. For example, consider the Harry Potter series. It is full of allusions to just about everything- the Bible, Shakespeare, and mythology. I am teaching Shakespeare’s play Macbeth right now. My students were shocked that the musical witches in Harry Potter, The Weird Sisters, actually came from Macbeth. They were flabbergasted that they did not originate with Harry Potter. Yet for readers familiar with Shakespeare, naming the band the Weird Sisters is a neat little inside joke, a play on the evil witches in Macbeth.