Tunneling splittings in -acetate single crystals E. del Barco, A. D. Kent, E. M. Rumberger, D. N. Hendrickson and G. Christou Europhys. Lett., 60 5 (2002) 768-774 Published online: 01 November 2002 DOI: 10.1209/epl/i2002-00374-9