I am having a surprisingly difficult time finding the original publication that used what is now called the Čech complex, named after Eduard Čech.
The Čech complex is well-known to be the nerve of the union of balls centered at each point in a metric space.
According to this nLab article, the idea for a simplicial complex determined by the nerve of a covering was independently investigated by Čech and Alexandrov in the 1920s, but it doesn't give any sources.
Does anyone know more about the history of the development of the Čech complex, including the original paper that used it (albeit perhaps not by name)? When was it first referred to as the Čech complex?
Edit. After some digging, I found a list of all his publications here. However, I'm not sure what title I'm looking for exactly.