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==References==
<references>
<ref name="Ag">A. Ageev, A. Kostochka, Z. Szigeti, ''A Characterization of Seymour Graphs'', Journal of Graph Theory, 24/4 (1997), 357-364. [http://dx.doi.org/10.1002/(SICI)1097-0118(199704)24:4%3C357::AID-JGT8%3E3.0.CO;2-N DOI link], [http://wwwpagesperso.g-scop.inpggrenoble-inp.fr/~szigetiz/articles/aksz.pdf Author link].</ref>
<ref name="Ag2">A. Ageev, Y. Benchetrit, A. Sebő, Z. Szigeti, ''An Excluded Minor Characterization of Seymour Graphs'', [http://dx.doi.org/10.1007/978-3-642-20807-2_1 DOI link].</ref>
