The Handbook of Global User Research has just been written by companies within the UX Alliance, an association of user experience agencies, who provide clients with a global service.
From the table of contents and a sample chapter, the book seems comprehensive in scope, covering traditional research techniques as well as eye tracking, unmoderated testing, and web analytics. This is reassuring and will be very interesting. A couple of people have posted positive reviews on Amazon.com
If you do global research yourself, you might find a host of tips and lessons. If you commission global research, you’ll have a better idea of what to expect (and ask for) from your agency.
Buy if for £34.19 from Amazon in the UK.