When I'm learning/researching a topic, I don't look for certain books, I read everything I can get my hands on. I do this simply because as I consume more and more of the related information, I can tell the difference between the good stuff and the bad stuff. Being able to tell the difference is a sign that your studying is paying off and that's why I'll read a book that may be boring and/or have bad reviews (to know why its bad material).
In addition to consuming everything I can, I also tend to gravitate to authors whom ideas are not my own or I even disagree with. I do this to gain perspective because I never know where I'll learn something valuable that may change my life for the better. That plus my own desire for depth of knowledge. With that being said, I have a couple books that may be of some use to you all:
First is Janine Driver - You Can't Lie to Me - This is her second book which made me go back to her first book "You Say More Than You Think". She provides model I like that doesn't just include body language, but looking at what the person is actually saying.
Philip Houston and other authors - Spy The Lie - This book seems to me to be about achieving the result and nothing more or less. Not sparing feelings or making people like you while you read them. Very straight forward read. I personally liked the use of what they call "stimulus" which is their word for what I'd say is a provoking question. They advise to use stimulus and pay close attention to the reactions after doing so.
Both books give ways to systematically look at both nonverbal and verbal language together for increasing your accuracy for lie detection. Hope this stimulates your mind guys and I'll be posting other books on related body language topics.