The first document describes competitive or distributive bargaining, which involves making high initial demands and small concessions while sharing little information. The goal is to get the best outcome for your side.
The second document describes interest-based negotiation, which aims to satisfy both parties' interests by expanding the total benefits and finding solutions that meet as many needs as possible.
The third document provides tips for different stages of negotiation including making small talk to build rapport, explaining your own position and interests, and asking questions to understand the other side.