Fractal aggregates induced by liposome-liposome interaction in the presence of Ca2+ J. Sabın, G. Prieto, J. M. Ruso and F. Sarmiento Eur. Phys. J. E, 24 2 (2007) 201-210 Published online: 14 November 2007 DOI: 10.1140/epje/i2007-10231-3