If you thought you have to remember the difficult search modifiers for Google to search for e-books and PDF files, this is where the PDF Search Engine makes our search easier. PDF Search Engine is a search engine that let users search for PDF files and with PDF documents, you get e-books as well, because most e-books are in PDF format. Just enter the keyword or phrase in the search box, and press Enter.

The search results are pretty relevant to what keywords we search and I always find what I’m looking for. You can search from the site, or add the browser extension to directly search from your browser.

Alternatively, you can also use Google Hacks to search PDF files on Google.

PDF Search Engine