I'm trying to find (without luck) the reduction for the Maximum Subforest Problem.
INSTANCE: Tree $G=\left(V,E\right)$ and a set of trees H.
SOLUTION: A subset $E'\subseteq E$ such that the subgraph $G'=\left(V,E'\right)$ does not contain any subtree isomorphic to a tree from H. MEASURE: Cardinality of the subgraph, i.e., $\vert E'\vert$.
Any idea on where I can find a paper or solution for this problem?