I see you recommended a few books and also said that 'a good book on negotiations will differentiate between strategies where the relationship is important and

I see you recommended a few books and also said that 'a good book on negotiations will differentiate between strategies where the relationship is important and where it isn't'. What is one such book? I'm new to negotiations, having been avoidant my whole life. I've started with GTY and Chris Voss's masterclass, but I know there's more out there. Someone here on HN mentioned once that 'salience models' are the now the cutting edge of negotiation theory, but I haven't been able to find much useful beginner/intermediate stuff on that.