My understanding is that map projections are essentially complex 
mathematical formulae, and as such cannot be copyrighted. Would date of 
release/development work? This list is not complete, but includes many: 
https://en.wikipedia.org/wiki/List_of_map_projections

Nat


On 11/7/16 3:37 PM, George Carhart wrote:
> can anyone tell me the best way to find a list of copyright dates for 
> world map projections developed in the 20th century.
>
> Thanks
> George Carhart
>
> -- 
>
> ---------------------------
> Dr. George S. Carhart, Ph.D
> Historian of Cartography
> and Early Modern Europe
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