Magnetic properties of the low dimensional spin system (VO)2P2O7: ESR and susceptibilityA. V. Prokofiev, F. Büllesfeld, W. Assmus, H. Schwenk, D. Wichert, U. Löw and B. LüthiEur. Phys. J. B, 5 3 (1998) 313-316DOI: https://doi.org/10.1007/s100510050448