It is going to sound silly but I need to select 2 PhD books out of 4 and I can't make up my mind. They all sound good. One of them is Australian, other is American and other 2 are from UK. Now I usually go for PhD-help books from the UK thinking they would be more familiar with the system here. But what do you think? Can a PhD book (on thesis writing) from America be as useful to a PhD student over here?

Nevermind...

probably too late but, i'd go for Australian. I find that its not too different and they're more practical.

Thanks jojo. I had to make a decision earlier and went for the Australian. I'm glad you suggested too, now it sounds like the right choice