Books

I’d like to read up on how people conduct their design research
i’ve searched amazon but don’t want to throw down cheese on a garbage book.

can anyone suggest a good one on design research?

alright, no replies so ill narrow my question
have any of the following books been helpfull, or not helpfull to anyone:

Design Research: Methods and Perspectives by Brenda Laurel and Peter Lunenfeld


A Designer’s Research Manual: Succeed in Design by Knowing Your Clients and What They Really Need (Design Field Guide) by Jennifer Visocky O’Grady and Kenneth Visocky O’Grady

and any others you could recomend would be fantastic. thanks