A couple of videos discussing this paper <a href="https://www.youtube.com/watch?v=MXb76NtoduA" rel="nofollow">https://www.youtube.com/watch?v=MXb76NtoduA</a> and <a href="https://www.youtube.com/watch?v=Wii1LX_ltIs" rel="nofollow">https://www.youtube.com/watch?v=Wii1LX_ltIs</a>, the last one within the context of Viewstamped Replication, which pre-dates Paxos and Raft.