What does "Google-fu" mean? [duplicate]

Google-fu is defined as "skill in using search engines (especially Google) to quickly find useful information on the Internet."

It is a somewhat tongue-in-cheek reference to kung-fu, which is generally perceived as requiring a high degree of skill to master in the western hemisphere.

In the example sentence you provided, the author is suggesting that the expected results are somewhat difficult to attain and you will need to use diligence when searching.

I used a bit of Google-fu to research this answer.

It means “mastery of Google” or “Googling skill”. It is modelled after kung fu:

kung fu (noun): a primarily unarmed Chinese martial art resembling karate.
ORIGIN from Chinese gōngfú, from gōng ‘merit’ + fú ‘master.’

It's a pormanteau of "Google" and "Kung-Fu," meaning to have high skill or art.