How can I find out if a book has a translation into another language?

1.  http://www.worldcat.org/ 2.  Enter the title of the book3.  On the next page, select the correct return4.  On the book's page, expand the languages list on the left.You can select the language you're looking for, and see the information about that edition.

I would start by writing the name of the author in the languages his works might have been translated to. That would be by hand. However, Suleman´s solution sounds much more thorough.

Thanks for the invite,

Simply, Google it!

You can use internet engines to search  

Expanding a bit on Joseph Smith's answer:1. Go to The World's Largest Library Catalog (the mentioned worldcat.org).2. Enter title of book, and it'd probably be helpful to select "Books" above the search bar.3. Search.4. Instead of clicking the title, click the small print "View all editions »" underneath the rest of the information.5. To the left and down a bit, there should be a box titled "Refine Your Search". "Language" is in there, and you can click "Show more..." to see all the languages, if there's more than five.This is as of29 March2015. The setup of the site may end up changing.

Asking persons who are specialist in books or searching on the internet can be helpful.

You can always Google it :)

And if Google couldn't help you, find and talk to a person having a P.hd in the present language of the book.

Thank You!

Frankly speaking, I am not an expert in literature, languages and translations, but I am interested in languages. I love and enjoy reading good, meaningful prose & poetry in Urdu & English.

So, answering to the question, I think to know that a book has been translated in other languages, mostly it is mentioned in the "Preface" or "Intro" of the book. Otherwise, Google is always there.... :)