Other vendors, such as Westlaw, also have Public Records databases --law students do not have access to them. Ask your employer if they have access to a public records system. Alternatively, determine where the public records you need are kept (Google should solve this most of the time). Then contact the appropriate office to retrieve them.
Finding people internationally can be a much bigger challenge than locating them within the US, since a lot of these tools will not provide information beyond US borders. If you need to locate someone for purposes of serving legal processes, seizing assets, or similar purposes, you may need to hire in-country investigators. You may also need to avail yourself of the special processes and pathways provided by various treaties and agreements between the US and the host country. For help getting started, see the US State Department's pages on international judicial assistance.
However, if you're just trying to find contact information, you can get pretty far with creative Googling. Here are a few frequently-useful strategies: