Cutwidth of the de Bruijn graph André Raspaud; Ondrej Sýkora; Imrich Vrt'o — 1995 RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
Outerplanar crossing numbers, the circular arrangement problem and isoperimetric functions. Czabarka, Éva; Sýkora, Ondrej; Székely, László A.; Vrt'o, Imrich — 2004 The Electronic Journal of Combinatorics [electronic only]