Generalized W-Class State and its Monogamy Relation
  We generalize the W class of states from $n$ qubits to $n$ qudits and prove that their entanglement is fully characterized by their partial entanglements even for the case of the mixture that consists of a W-class state and a product state $\ket{0}^{\otimes n}$. 
Jeong San Kim and Barry C. Sanders