1. Greenʼs Functions in Quantum Physics;Economou,2006
2. Greenʼs Functions for Solid State Physicists;Doniach,1998
3. Symmetry and Condensed Matter Physics. A Computational Approach;El-Batanouny,2008
4. Spin-waves impurity states in ferromagnets;Wolfram;Phys. Rev.,1963
5. Random walks on lattice. II;Montroll;J. Math. Phys.,1965