The reference for the first appearance of the conjecture (still without the condition that the PD group has to be a priori finitely presented) seems to be http://www.worldcat.org/title/homological-group-theory-proceedings-of-a-symposium-held-at-durham-in-september-1977-on-homological-and-combinatorial-techniques-in-group-theory/oclc/6022486 from 1977.
You find a survey on the state of the subject around 2000 in Davis: "Poincaré duality groups".