His work was shown to J V Uspenskii, a student of A A Markov, who saw that Frenkel had discovered many results on finite differences for himself.
Kanyang trabaho ay ipinapakita sa JV Uspenskii, isang mag-aaral ng AA Markov, na na maglagari Frenkel had natuklasan ng maraming mga resulta sa wakas pagkakaiba sa kanyang sarili.