A Necessary and Sufficient Condition for the Existence of a Heterochromatic Spanning Tree in a Graph.

Kazuhiro Suzuki A Necessary and Sufficient Condition for the Existence of a Heterochromatic Spanning Tree in a Graph. 261-269 2006 22 Graphs and Combinatorics 2 http://dx.doi.org/10.1007/s00373-006-0662-3 db/journals/gc/gc22.html#Suzuki06