You can find PhD thesis online through several platforms and databases. Key sources include institutional repositories like those from universities, which often host theses by their graduates. Global databases such as ProQuest Dissertations & Theses provide extensive access to theses from various institutions. Additionally, Google Scholar can be useful for locating theses and dissertations. For open-access theses, platforms like the Networked Digital Library of Theses and Dissertations (NDLTD) offer a comprehensive collection. Checking specific university libraries' digital collections is also a good strategy.