Consider using Library of Congress Subject Headings. Make sure you enter last name, then first name and then be sure to search them by Subject (preferable) or by Keyword (not as author, otherwise you will only find works written by them).
[Last Name of Person], [First Name of Person]
Examples:
Beauvoir, Simone De
Gandhi, Mahatma
Locke, John
Satre, Jean-Paul
Camus, Albert
