When it comes to prepare research reports or seminar papers , you will probably need to find PDF files online for reference. After entering your query on Google, it surely does it job well but it does not show particularly the file types you want. Read on to know how you can save your time searching PDF files online with an ease.

You can use two online services to do this or you can say PDF search engines. PDF Database is one such new tool which uses a unique system for searching PDF and doc files from all over the net. Its database is huge- more than 7million PDF and document file and still it growing.

Another excellent option is PDF Search Engine which displays relevant results after entering the keyword of the document you want. These both services have great database and response time is also nice.