Shari Y. Manning

The best of the BPD books that I've read. It really describes the BPD/non-BPD relationship (which could be useful for many types of relationships, not just the ones that are with someone with diagnosed BPD), and it has useful tips for communicating and de-escalating (also good for all sorts of relationships). That said, just reading it felt like a lot of emotional work. It's pretty much therapist-level relationship management skills.