How to download all PDF files from a website using wget but every link is a database query

This is the search form

http://ift.tt/1esEVde

Fill Pesquisa livre field with something like rio

Every link you will see, if clicked, will lead to a page that contains a PDF file.

My problem is that this page is a form that is querying a database.

Is that possible to use wget with a URL that is a query get all PDFs that the result pages contain? how?

I have tried this command and it is failing

wget -r -A pdf http://ift.tt/1RluMgv

thanks.