Q. How can I find some articles about the philosopher Gottfried Wilhelm Leibniz?

A good place to get articles on philosophers is our philosophy databases.  You can click on each individual database and type in Gottfried Wilhelm Leibniz in the search field to retrieve information on the philosopher.  Use the database filters on the side of the screen to limit your results to full text articles, and other criteria you have.  I did a search using ProQuest, typing in Gottfried Wilhelm Leibniz and using the Scholarly Journals and English language filters on the left side of the screen and was able to retrieve several articles with information on him.

Gale OneFile Religion and Philosophy and JSTOR would also be good databases to try searching for this philosopher.  

You can use the library's catalog, OneSearch, to get a list of resources and information the library makes available on Leibniz.  Type his name into the Search field and use the filters at the side of the screen to narrow down your results.