Olmer, Jane and Rich, Robert "A Flexible Direct File Approach to Information Retrieval on a Small to Medium Size Computer"

[AFIPS JCC 24] Proceedings of the 1963 Fall Joint (1963) [AFIPS JCC 24] Proceedings of the 1963 Fall Joint Computer Conference FJCC 1963, Las Vegas, Nev., Nov. 1963,  

Languages mentioned APT {1960} Polish notation algebraic language