All I can remember is that it was very **high-level / abstact and kind of philosophical**, explaining **(the discovery or interdependence of) small world networks**. I assume that it was **+50 years old** and 'might' be an iconic paper, but maybe not - surely it was by far not as popular as the, already mentioned, paper "small world networks and their dynamics" by Duncan J. Watts & Steven H. Strogatz, but also it was on a completely different level of math.


I think I found it once on [Azimuth](https://johncarlosbaez.wordpress.com/) Blog from John Carlos Baez. But it is very large and I don't even find "small world network" in the search (it might have also been mentioned by someone in the comment section).



Searching for an early, highly theoretical, even philosophical, math paper on models or small-world networks
Stanley Milgram, [The Small World Problem](http://snap.stanford.edu/class/cs224w-readings/milgram67smallworld.pdf), Psychology Today **2**, 60 (1967)


seems to fit the bill: +50 years old, "kind of philosophical", and yes, iconic -- cited more than 9,000 times. There are a few related papers in that time frame, listed [here,](https://en.wikipedia.org/wiki/Six_degrees_of_separation#Small_world) but the paper from Psychology Today had the largest impact.


