Steffensen's inequality and Steffensen's method (an iterative numerical method) are named after him.
Johan Christian Fabricius | Frederik Pohl | Johan Galtung | Frederik Magle | Frederik, Crown Prince of Denmark | Johan Petter Johansson | Johan Norberg | Johan Niclas Byström | Johan Museeuw | Johan Henric Kellgren | Johan de Witt | Johan Jeremiassen | Johan Gunnar Andersson | Johan Cruyff | Johan Bojer | Frederik van Eeden | Frederik de Groot | Nils Johan Berlin | Johan Wohlert | Johan Vande Lanotte | Johan Svendsen | Johan Reinhard | Johan Jakobsson | Johan Ferrier | Johan Falkberget | Johan de Meij | Johan Banér | Frederik Ruysch | Willem Frederik Hermans | Ulrik Frederik Gyldenløve |