I am new to the field of vertex partition problems and I have the following problem:
For a given graph $G(x,z)$ with $x$ nodes, $z$ edges and node weights $t: x \rightarrow \mathbb{R}$, partition the graph into $k$ connected components with $x_1 \cup x_2 \cup...,x_k = x$ and $x_1 \cap x_2 \cap...,x_k = \Phi$ such that the total sum of node weights in each partition is minimized.
I have come across a note in the book "Computers and Intractability" that says,
However, I am not able to find the report "Graph partitioning and constructing optimal decision trees are polynomial complete problems" as only two copies exist in Germany.
I am wondering if anyone could point me to a right direction that can help me prove the problem I have is NP-complete.