Summarising Pfeiffer's work in, KovAl-chuk says that Pfeiffer's methods greatly expanded the class of integrable systems, but have been neglected over the past half-century as functional-analytic methods have been in fashion.
Summarising Pfeiffer ng trabaho sa, KovAl-chuk na nagsasabing Pfeiffer ng mga pamamaraan ng malaki pinalawak na ang klase ng integrable sistema, ngunit ay napapabayaan sa nakaraang kalahating siglo bilang functional-analytic pamamaraan ay sa fashion.