https://books.google.com/ngrams/graph?content=Keith+Hernandez%2CDziga+Vertov&year_start=1800&year_end=2000&corpus=15&smoothing=5&share=&direct_url=t1%3B%2CKeith%20Hernandez%3B%2Cc0%3B.t1%3B%2CDziga%20Vertov%3B%2Cc0