I recently came to know about this website called PDF Search Engine that I found quite useful, and thought of sharing it with all of you here. It is a search engine that allows you to find PDF files on sites, forums and message boards.
All you need to do is type in the keyword/ name/ title of what you’re looking for and it would list the related PDF files for you.
For instance, when I was searching for the RBI notification on free ATM cash withdrawals for my first post on Devils Workshop, I tried to use this tool and very easily found the PDF file I had been looking for.
Although, I am not very sure if the search will always be this easy, as the engine generates a huge list of search results on the key words that you type, some of which aren’t even relevant.
But from what I’ve heard and my own experience, this search engine often comes in handy when you’re looking for an e-book, or some PDF document you couldn’t locate otherwise.
I think it wouldn’t hurt to give it a try. It worked for me! 
Link: PDF Search Engine
Google Rocks! It throws up everything you need. Still, I’ll keep this in mind in case Google falls sick some day
Thx,
Hash!
@ Hash,
I agree. Google does it all. However, some good search engines do make your results more accurate and save time.
This tool doesn’t seem to be very helpful though. Tried it a couple of times.
pdf search, ppt search, doc search all available in googlengoogle website. This is india’s first vertical search engine.