Start with tertiary sources, which will often provide bibliographic details for and sometimes even evaluations of translations.
Depending on the amount of information that you have, you'll need to use one or more of these pathways to actually get ahold of the translation you seek.
Option A: Known-item Searching
If you have the full or nearly bibliographic information, such as author, title in English, name of translator, publisher, and year of publication, then you can run an advanced search in Primo to locate the material. Remember to sign in so that you'll be able to request materials from SUMMIT.
For example, suppose you've discovered, via searching the Literature Resource Center, that "The hut on the roof," by Hiromi Kawakami, has been translated by Lucy Fraser and appears in the anthology The Book of Tokyo: A City in Fiction (Manchester: Comma, 2015). By searching Primo for the title of either the anthology (Book of Tokyo) or the short story, "The Hut on the Roof," and the author name, you'll find that you can request the anthology from a Summit library.
Option B: Author searching
If you only know the author's name, there are two ways to try to search Primo:
Option C: Searching Anthologies, Collections, and Literary Magazines
Translations of works, especially poems and short stories, that appear in anthologies are not always discoverable via author and/or title searching in Primo. Try searching Google Books to see if you can get the bibliographic information, and then search Primo again with the new information. If that also fails to yield results, then you may need to browse through anthologies, using one or more of these methods:
China -- Literary collections (then limit results to English)
Japan -- Literary collections (then limit results to English only)
Korea -- Literary collections (then limit results to English)
2. Search literary magazines that publish translations into English: