I'm guessing this question is unresolvable, given that nine year old Milton never specified where he got the idea of the google word. Apparently Larry found it

I'm guessing this question is unresolvable, given that nine year old Milton never specified where he got the idea of the google word. Apparently Larry found it a convincing enough story that the first book scanned for Google books was The Google Book, which was itself th source for the name Barney Google.