Write the following list of characters into a correctly formed sentence: In1891,Stackel'shabilitationthesis,IntegrationofHamiltonian-Jacobiandifferentialequationsbymeansofseparationofvariables,wasacceptedbytheUniversityofHalle,nearLeipzig,andhetookupalectureshipthere.
In 1891, Stackel's habilitation thesis, Integration of Hamiltonian-Jacobian differential equations by means of separation of variables, was accepted by the University of Halle, near Leipzig, and he took up a lectureship there.