Where can I find authors' pseudonyms?
A good, authoritative source for answering this question is Encyclopedia Britannica, which typically lists the pseudonyms that an author has used. You can access it here:
On Britannica's main page, there is a "Browse" section in which you can select "Biographies". This will present you with a long list of individuals, which you can limit to authors by selecting entries from the Literature category in the "Topic" drop-down list. Placing the cursor over any of the names in this list will display the first few sentences of the encyclopedia entry for that person. If an author has written under a pseudonym, it will typically be mentioned in these first few sentences.
You can get more information about using Encyclopedia Britannica and similar online reference tools in our How to Use Reference Databases Libguide.