1. As comprehensive reviews, “Relaxations of Excited States and Photoinduced Structural Phase Transitions”, editd by K. Nasu (Springer-Verlag, Berlin 1997), “Photo induced Phase Transitions”, edited by K. Nasu (World Scientific publishing, Singapore, 2004) and K. Yonemitsu and K. Nasu, J. Phys. 465, 1 (2008)
2. M. Imada, A. Fujimori, Y. Tokura, Rev. Mod. Phys. 70, 1039 (1998)
3. K. Miyano, T. Tanaka, Y. Tomioka, Y. Tokura, Phys. Rev. Lett. 78, 4257 (1997)
4. A. Cavalleri, M. Rini, H.H.W. Chong, S. Fourmaux, T.E. Glover, P.A. Heimann, J.C. Kieffer, R.W. Schoenlein, Phys. Rev. Lett. 95, 067405 (2005)
5. For example, “Spin Crossover in Transition Metal Compounds I, II and III”, edited by P (Goodwin (Springer Verlag, Berlin Heidelberg, Gutlich and H. A, 2004)