treat serious subjects in a playful and humorous way: for example, the way Heller and Vonnegut address the events of World War II. The central concept of Heller's Catch-22 is the irony of the now-idiomatic "catch-22", and the narrative is structured around a long series of similar ironies. Thomas Pynchon's The Crying of Lot 49 in particular provides prime examples of playfulness, often including silly wordplay, within a serious context. For example, it contains characters named Mike Fallopian and Stanley Koteks and a radio station called KCUF, while the novel as a whole has a serious subject and a complex structure. Intertextuality Since postmodernism represents a decentred concept of the universe in which individual works are not isolated creations, much of the focus in the study of postmodern literature is on intertextuality: the relationship between one text (a novel for example) and another or one text within the interwoven fabric of literary history. Intertextuality in postmodern literature can be a reference or parallel to another literary work, an extended discussion of a work, or the adoption of a style. In postmodern literature this commonly manifests as references to fairy tales—as in works by Margaret Atwood, Donald Barthelme, and many others—or in references to popular genres such as sci-fi and detective fiction. Often intertextuality is more complicated than a single reference to another text. Robert Coover's Pinocchio in Venice, for example, links Pinocchio to Thomas Mann's Death in Venice. Also, Umberto Eco's The Name of the Rose takes on the form of a detective novel and makes references to authors such as Aristotle, Sir Arthur Conan Doyle, and Borges. An early 20th century example of intertextuality which influenced later postmodernists is "Pierre Menard, Author of the Quixote" by Jorge Luis Borges, a story with significant references to Don Quixote which is also a good example of intertextuality with its references to Medieval romances. Don Quixote is a common reference with postmodernists, for example Kathy Acker's novel Don Quixote: Which Was a Dream. References to Don Quixote can also be found in Paul Auster's post-modern detective story, City of Glass. Another example of intertextuality in postmodernism is John Barth's The Sot-Weed Factor which deals with Ebenezer Cooke's poem of the same name. Pastiche Related to postmodern intertextuality, pastiche means to combine, or "paste" together, multiple elements. In Postmodernist literature this can be a homage to or a parody of past styles. It