Use the Databases tab in this Research Starter to look for more articles. Search by the theorist's name or theory and once you have located some useful articles, look at Subject Terms or Keywords within the individual articles for more suggestions on search terms. Some databases may have links near the article titled More like this or Find Similar Results that might be helpful to you.
Always look at the list of References; Works Cited; or the Bibliography found at the end of any particularly useful article for other books, articles, videos, etc. Resources not available full-text may be requested through our free InterLibrary Loan Service.
Additionally, don't forget that you can ask a librarian for assistance.