Preparation, magnetoresistance and magnetocaloric effect of two-layered perovskite La2.5-xK0.5+xMn2O7+δW. Zhong, W. Chen, H. Y. Jiang, X. S. Liu, C. T. Au and Y. W. DuEur. Phys. J. B, 30 3 (2002) 331-337DOI: https://doi.org/10.1140/epjb/e2002-00386-3