Classical simulation of quantum algorithms using the tensor product   representation
  Using the tensor product representation in the density matrix renormalization group, we show that a quantum circuit of Grover's algorithm, which has one-qubit unitary gates, generalized Toffoli gates, and projective measurements, can be efficiently simulated by a classical computer. It is possible to simulate quantum circuits with several ten qubits. 
A. Kawaguchi, K. Shimizu, Y. Tokura and N. Imoto