We present paraconductivity (AL) measurements in three different high temperature superconductors: a melt textured YBa_2Cu_3O_7 sample, a Bi_2Sr_2CaCu_2O_8 epitaxial thin film and a highly textured Bi_2Sr_2Ca_2Cu_3O_10 tape. The crossovers between different temperature regimes in excess conductivity have been analysed. The Lawrence-Doniach (LD) crossover, which separates the 2D and 3D regimes, shifts from lower to higher temperatures as the compound anisotropy decreases. Once the LD crossover

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... overcome, the fluctuation conductivity of the three compounds shows the same universal behaviour: for ϵ = T/T_c > 0.23 all the curves bend down according to the 1/ϵ^3 law. This asymptotic behaviour was theoretically predicted previously for the high temperature region where the short wavelength fluctuations (SWF) become important.