Sterol evolution and the physics of membranes M. Nielsen, J. Thewalt, L. Miao, J. H. Ipsen, M. Bloom, M. J. Zuckermann and O. G. Mouritsen Europhys. Lett., 52 3 (2000) 368-374 Published online: 01 September 2002 DOI: 10.1209/epl/i2000-00448-8