Ironically the very first publication on "Backpropagation" by a Finish master student (1972) already pointed out how to compute gradients in computational graph

Ironically the very first publication on "Backpropagation" by a Finish master student (1972) already pointed out how to compute gradients in computational graphs. This if anything is the main thing which distinguishes Backpropagation as an algorithm from simply applying the chain rule.