@article{21827,
  author       = {{Klopp, Antje and Steffen, Eckhard}},
  issn         = {{0911-0119}},
  journal      = {{Graphs and Combinatorics}},
  pages        = {{559--580}},
  title        = {{{Fractional Matchings, Component-Factors and Edge-Chromatic Critical Graphs}}},
  doi          = {{10.1007/s00373-020-02266-6}},
  year         = {{2021}},
}

@article{13445,
  author       = {{Steffen, Eckhard and Vogel, Alexander}},
  journal      = {{European J. Combinatorics}},
  title        = {{{Concepts of signed graph coloring}}},
  volume       = {{91}},
  year         = {{2021}},
}

@article{13114,
  author       = {{Lu, You and Luo, Rong and Schubert, Michael and Steffen, Eckhard and Zhang, Cun-Quan}},
  journal      = {{SIAM J. Discrete Math}},
  pages        = {{2166--2187}},
  title        = {{{Flows on signed graphs without long barbells}}},
  doi          = {{10.1137/18M1222818}},
  volume       = {{34 (4)}},
  year         = {{2020}},
}

@article{12971,
  author       = {{Jin, Ligang and Steffen, Eckhard}},
  journal      = {{J. of Combinatorics}},
  pages        = {{457--473}},
  title        = {{{Unions of 1-factors in r-graphs and overfull graphs}}},
  volume       = {{11}},
  year         = {{2020}},
}

@inbook{16938,
  author       = {{Engels, Gregor and Maier, Günter W. and Ötting, Sonja K. and Steffen, Eckhard and Teetz, Alexander}},
  booktitle    = {{Zukunft der Arbeit – Eine praxisnahe Betrachtung}},
  editor       = {{Wischmann, Steffen and Hartmann, Ernst Andreas}},
  isbn         = {{9783662492659}},
  pages        = {{221--231}},
  publisher    = {{Springer Verlag}},
  title        = {{{Gerechtigkeit in flexiblen Arbeits- und Managementprozessen}}},
  doi          = {{10.1007/978-3-662-49266-6_16}},
  year         = {{2018}},
}

@article{10129,
  abstract     = {{There are many hard conjectures in graph theory, like Tutte's 5-flow conjecture, and the 5-cycle double cover conjecture, which would be true in general if they would be true for cubic graphs. Since most of them are trivially true for 3-edge-colorable cubic graphs, cubic graphs which are not 3-edge-colorable, often called snarks, play a key role in this context. Here, we survey parameters measuring how far apart a non 3-edge-colorable graph is from being 3-edge-colorable. We study their interrelation and prove some new results. Besides getting new insight into the structure of snarks, we show that such  measures give partial results with respect to these important conjectures. The paper closes with a list of open problems and conjectures.}},
  author       = {{Fiol, M. A. and Mazzuoccolo, Guiseppe and Steffen, Eckhard}},
  journal      = {{The Electronic Journal of Combinatorics}},
  keywords     = {{Cubic graph, Tait coloring, Snark, Boole coloring, Berge's conjecture, Tutte's 5-flow conjecture}},
  number       = {{4}},
  title        = {{{Measures of Edge-Uncolorability of Cubic Graphs}}},
  volume       = {{25}},
  year         = {{2018}},
}

@article{10130,
  author       = {{Rollová, Edita and Schubert, Michael and Steffen, Eckhard}},
  journal      = {{The Electronic Journal of Combinatorics}},
  number       = {{2}},
  title        = {{{Flows in Signed Graphs with Two Negative Edges }}},
  doi          = {{10.37236/4458}},
  volume       = {{25}},
  year         = {{2018}},
}

@article{10132,
  author       = {{Jin, Ligang and Mazzuoccolo, Giuseppe and Steffen, Eckhard}},
  issn         = {{1234-3099}},
  journal      = {{Discussiones Mathematicae Graph Theory}},
  pages        = {{165--175}},
  title        = {{{Cores, joins  and the Fano-flow conjectures}}},
  doi          = {{10.7151/dmgt.1999}},
  volume       = {{38}},
  year         = {{2018}},
}

@article{10142,
  author       = {{Steffen, Eckhard}},
  journal      = {{Australasian Journal of Combinatorics}},
  number       = {{1}},
  pages        = {{153--160}},
  title        = {{{Approximating Vizing’s independence number conjecture}}},
  volume       = {{71}},
  year         = {{2018}},
}

@book{10146,
  editor       = {{Maier, Günter W. and Engels, Gregor and Steffen, Eckhard}},
  publisher    = {{Springer Berlin Heidelberg}},
  title        = {{{Handbuch Gestaltung digitaler und vernetzter Arbeitswelten}}},
  year         = {{2017}},
}

@inbook{10147,
  author       = {{Simon, Dagmar and Steffen, Eckhard}},
  booktitle    = {{Handbuch Gestaltung digitaler und vernetzter Arbeitswelten,}},
  editor       = {{Maier, Günter W. and Engels, Gregor and Steffen, Eckhard}},
  pages        = {{1--12}},
  publisher    = {{Springer Berlin Heidelberg}},
  title        = {{{Digitale Zukunft: ein inter- und transdisziplinäres Thema}}},
  year         = {{2017}},
}

@article{10155,
  author       = {{Mazzuoccolo, Guiseppe and Steffen, Eckhard}},
  journal      = {{J. Graph Theory}},
  pages        = {{363 – 371 }},
  title        = {{{Nowhere-zero 5-flows on cubic graphs with oddness 4}}},
  volume       = {{85}},
  year         = {{2017}},
}

@article{10156,
  author       = {{Bej, Saptarshi and Steffen, Eckhard}},
  journal      = {{Lecture Notes of Seminario Interdisciplinare di Matematica}},
  pages        = {{37--48}},
  title        = {{{Factors of edge-chromatic critical graphs: a brief survey and some equivalences}}},
  volume       = {{14}},
  year         = {{2017}},
}

@article{10157,
  author       = {{Jin, Ligang and Steffen, Eckhard}},
  journal      = {{J. Graph Theory}},
  pages        = {{109 -- 120 }},
  title        = {{{Petersen cores and the oddness of cubic graphs}}},
  volume       = {{84}},
  year         = {{2017}},
}

@article{10158,
  author       = {{Jin, Ligang and Kang, Yingli and Steffen, Eckhard}},
  journal      = {{Electronic Journal of Combinatorics}},
  number       = {{3}},
  title        = {{{Face-degree bounds for planar critical graphs}}},
  volume       = {{23}},
  year         = {{2016}},
}

@article{10159,
  author       = {{Kang, Yingli and Steffen, Eckhard}},
  journal      = {{Discrete Mathematics }},
  pages        = {{234--243}},
  title        = {{{The chromatic spectrum of signed graphs}}},
  volume       = {{339}},
  year         = {{2016}},
}

@article{10160,
  author       = {{Jin, Ligang and Kang, Yingli and Steffen, Eckhard}},
  journal      = {{Discrete Applied Mathematics}},
  pages        = {{200–202}},
  title        = {{{Remarks on planar critical graphs}}},
  volume       = {{200}},
  year         = {{2016}},
}

@article{10161,
  author       = {{Jin, Ligang and Kang, Yingli and Steffen, Eckhard}},
  journal      = {{European J. Combinatorics}},
  pages        = {{234--243}},
  title        = {{{Choosability in signed planar graphs}}},
  volume       = {{52}},
  year         = {{2016}},
}

@article{10162,
  author       = {{Steffen, Eckhard}},
  journal      = {{Combinatorica}},
  pages        = {{633--640}},
  title        = {{{Intersecting 1-factors and nowhere-zero 5-flows}}},
  volume       = {{35}},
  year         = {{2015}},
}

@article{10163,
  author       = {{Steffen, Eckhard}},
  journal      = {{J. Graph Theory}},
  pages        = {{1--7}},
  title        = {{{Edge-colorings and circular flow numbers of regular graphs}}},
  volume       = {{79}},
  year         = {{2015}},
}