Cappello, Chiara, and Eckhard Steffen. “Symmetric Set Coloring of Signed Graphs.”https://doi.org/10.1007/s00026-022-00593-4__Annals of Combinatorics, 2022.https://doi.org/10.1007/s00026-022-00593-4 .

Cappello, Chiara, and Eckhard Steffen. “Frustration-Critical Signed Graphs.”https://doi.org/10.1016/j.dam.2022.08.010__Discrete Applied Mathematics 322 (2022): 183–93.https://doi.org/10.1016/j.dam.2022.08.010 .

Li, Jiaao, Yulai Ma, Zhengke Miao, Yongtang Shi, Weifan Wang, and Cun-Quan Zhang. “Nowhere-Zero 3-Flows in Toroidal Graphs.”https://doi.org/10.1016/j.jctb.2021.11.001__Journal of Combinatorial Theory, Series B 153 (2021): 61–80.https://doi.org/10.1016/j.jctb.2021.11.001 .

Li, Jiaao, Yulai Ma, Yongtang Shi, Weifan Wang, and Yezhou Wu. “On 3-Flow-Critical Graphs.”https://doi.org/10.1016/j.ejc.2021.103451__European Journal of Combinatorics 100 (2021).https://doi.org/10.1016/j.ejc.2021.103451 .

Fiol, M. A., Guiseppe Mazzuoccolo, and Eckhard Steffen. “Measures of Edge-Uncolorability of Cubic Graphs.” The Electronic Journal of Combinatorics 25, no. 4 (2018).

Jin, Ligang, Giuseppe Mazzuoccolo, and Eckhard Steffen. “Cores, Joins  and the Fano-Flow Conjectures.”https://doi.org/10.7151/dmgt.1999__Discussiones Mathematicae Graph Theory 38 (2018): 165–75.https://doi.org/10.7151/dmgt.1999 .

Steffen, Eckhard. “Approximating Vizing’s Independence Number Conjecture.” Australasian Journal of Combinatorics 71, no. 1 (2018): 153–60.

Steffen, Eckhard. “Nearly Nowhere-Zero r-Flow Graphs.” Discrete Mathematics 312 (2012): 2757–59.