Some alternate editions of the assigned readings may be found online. For example the Hathi Trust Public Domain collection includes these two editions of Leaves of Grass:
Whitman, Walt. Leaves of Grass. Philadelphia: D. McKay, Washington Square, 1900. [including a fac-simile autobiography, variorum readings of the poems and a department of gathered leaves]
Whitman, Walt, and Valenti Angelo. Leaves of Grass. New York: Modern Library, 1933. [comprising all the poems written by Walt Whitman following the arrangement of the edition of 1891-'2.]
Here are more Literature Specific Databases that you should search for your topic in.
Question: Why would you use Google Scholar?
Answer: Google Scholar identifies scholarly research materials from a broad range of subject areas.
Google Scholar offers a "cited by" feature - it will display a list of documents which cited the document you originally retrieved. This can be useful in determing how influential a source has been. The list only includes documents available in Google Scholar, though.
Go into the preferences of Google Scholar and select Pepperdine University from Library Links.