Searching Google or another search engine using a particular mathematician's name, for example: Hypatia, Euler or Ramanujan, will help you find web sites with biographical information specific to that person. Here are some general biographical web sites for mathematicians.
You can also find biographies of particular mathematicians searching on their names in DELCAT, the University Libraries' catalog. The Library of Congress Subject Headings, used in DELCAT Discovery, has several terms that enable you to identify biographical sources. Video tutorial to using DELCAT.
Sample subject searches in DELCAT (UD library only):
1) Mathematicians AND biography
search syntax => Subject contains: Mathematicians AND Subject contains: Biography
search syntax => Subject contains exact phrase: Women Mathematicians
3) Mary Somerville, 1780-1872
search syntax => Subject contains exact phrase: Mary Somerville
Sample subject searches in DELCAT (UD library and libraries worldwide results):
1) Mathematicians AND biography
search syntax => Subject contains: Mathematicians AND Subject contains: Biography
search syntax => Subject contains exact phrase: Women Mathematicians
3) Mary Somerville, 1780-1872
search syntax => Subject contains exact phrase: Mary Somerville
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