His later work covered a wide range of different topics in geomery and analysis including Borel functions, Hausdorff measure and local measure, topological properties of Banach spaces and upper semicontinuous functions.
Kanyang trabaho mamaya sakop ng isang malawak na hanay ng iba't-ibang mga paksa sa geomery at pagtatasa Borel kabilang ang mga pag-andar, Hausdorff masukat at lokal na masukat, topological pag-aari ng Banach espasyo at itaas semicontinuous function.