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@article{ARM_1991__27_1-2_a15, author = {Zelinka, Bohdan}, title = {Every connected acyclic digraph of height 1 is neighbourhood-realizable}, journal = {Archivum mathematicum}, pages = {133--135}, publisher = {mathdoc}, volume = {27}, number = {1-2}, year = {1991}, mrnumber = {1189650}, zbl = {0758.05056}, language = {en}, url = {http://geodesic.mathdoc.fr/item/ARM_1991__27_1-2_a15/} }
Zelinka, Bohdan. Every connected acyclic digraph of height 1 is neighbourhood-realizable. Archivum mathematicum, Tome 27 (1991) no. 1-2, pp. 133-135. http://geodesic.mathdoc.fr/item/ARM_1991__27_1-2_a15/