While the theme of "Ode on a Grecian Urn" focuses on how art is eternal, the theme of "Ozymandias" focuses on how

royalty is superior.
nature endures.
things change.
deserts are lonely.

In mla style, the works cited page provides information about all the sources cited within the paper or document written. it is often place at the end of the work and it generally   contains the complete name of the author, name of the book/article, etc, place and date.