Many attempts had been done to estimate dynamical masses of galaxies at intermediate redshifts. They lead to Tully-Fisher relations with very large scatters, rending uneasy further tests on the evolution of the relation between dark and visible matter. The use of multiple integral field units such as the 15 IFU of FLAMES/GIRAFFE at VLT revolutionizes these investigations. This facility is able to recover the velocity fields of almost all the emission line galaxies with I(AB)
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