@article{Kloetzler, author = {Kl{\"o}tzler, Rolf}, title = {Strong duality for transportation flow problems}, language = {en} } @incollection{PickenhainKloetzler, author = {Pickenhain, Sabine and Kl{\"o}tzler, Rolf}, title = {Pontryagin's maximum principle for multidimensional control problems}, series = {Optimal control, Conference on Optimal Control, held at the Mathematisches Forschungsinstitut of the University of Freiburg}, booktitle = {Optimal control, Conference on Optimal Control, held at the Mathematisches Forschungsinstitut of the University of Freiburg}, editor = {Bulirsch, Roland}, publisher = {Birkh{\"a}user}, address = {Basel [u.a.]}, isbn = {0-8176-2887-8}, pages = {21 -- 30}, language = {en} } @techreport{Kloetzler, author = {Kl{\"o}tzler, Rolf}, title = {In welchem Sinne wurde das 23. Hilbert-Problem bisher gel{\"o}st?}, publisher = {Brandenburgische Techn. Univ., Fak. f{\"u}r Mathematik, Naturwiss. und Informatik}, address = {Cottbus}, pages = {11}, language = {de} }