Optical character recognition software for Ubuntu

I found this publication from 1898 ( http://gazette.slv.vic.gov.au/images...general/72.pdf ) that is a scaed document in PDF formant. The file is 64 pages long and there are certain keywords that I'm looking for.

Since the doc is a scan, I can't just do a ctrl-F and do a search.

I'm wondering if there is any OCR software available on Ubuntu that I could download that would allow me to search for keywords. Alteatively, if there is another method to search for keywords that someone could advise me of, that would be appreciated.

Thank you