  The possibility of determining cosmological parameters on the basis of a wide
set of observational data including the Abell-ACO cluster power spectrum and
mass function, peculiar velocities of galaxies, the distribution of Ly-$\alpha$
clouds and CMB temperature fluctuations is analyzed. Using a $\chi^2$
minimization method, assuming $\Omega_{\Lambda}+\Omega_m =1$ and no
contribution from gravity waves, we found that a tilted $\Lambda$MDM model with
one sort of massive neutrinos and the parameters $n\approx 1.12$,
$\Omega_m\approx 0.4$ ($\Omega_{\Lambda}\approx 0.6$), $\Omega_{cdm}\approx
0.3$, $\Omega_{\nu}\approx 0.06$, $\Omega_b\approx 0.04$ and $h\approx 0.7$
matches observational data best. $\Omega_{\nu}$ is higher for more species of
massive neutrinos, $\sim 0.1$ for two and $\sim 0.13$ for three species.
$\Omega_m$ raises by $\sim 0.08$ and $\sim 0.15$ respectively.
  Varying only a subset of parameters and fixing the others shows also that the
observational data set used here rules out pure CDM models with $h\ge 0.5$,
scale invariant primordial power spectrum, zero cosmological constant and
spatial curvature at a very high confidence level, $>99.99%$. The corresponding
class of MDM models are ruled out at $\sim 95%$ C.L.
  It is notable also that this data set determines the amplitude of scalar
fluctuations approximately at the same level as COBE four-year data. It
indicates that a possible tensor component in the COBE data cannot be very
substantial.
