Fenyő also wrote historical math articles and papers throughout his life. Specifically, he wrote about Lipót Fejér and Frigyes Riesz in two of his works, "Some aspects of the relations between Italian and Hungarian mathematicians" and "L. Fejér et F. Riesz-100.Geburtstag". The first work covers the relationship of those two mathematicians "with Italian mathematicians during the inter-War period", whereas the second work includes the biographies of Fejér and Riesz.
