Some Classic Papers
On the evolution of logic programming Kowalski
On logic programming Emden and Kowalski
The Method for automated deduction by Martin Davis and Hilary Putnam
Improvement of Davis Putnam by Logemann and Loveland DPLL Algorithm
Axiomatic Semantics Hoare
The Idea behind Hoare semantics originated with this paper Floyd
Dijkstra's paper (guarded semantics - mutual exclusion) Dijkstra
Plotkin's report on Operational Semantics Plotkin