Further to my other reply, I've just checked the intertubes, and found that Codd's paper "A Relational Model of Data for Large Shared Data Banks" was published

Further to my other reply, I've just checked the intertubes, and found that Codd's paper "A Relational Model of Data for Large Shared Data Banks" was published in 1970, and Dijkstra's "Go To Statement Considered Harmful" in 1968. So I think my fading memories of all this are accurate (for once!).