To find copies of specific magazines, search by title in Tripod Books & More and limit your results to "journal title." (You can also search in WorldCat for items not held by the TriCo.)
To identify little magazines about which you do not already know, you can either consult appropriate secondary sources (e.g., The Oxford Critical and Cultural History of Modernist Magazines), which you can find using subject headings like these:
Or you can use the following subject headings in Tripod or WorldCat to find the magazines directly. (Search in the subject field for "periodicals" to identify additional subject headings.)