  Using a recently developed scaling procedure that allows to establish the
temperature dependence of the normalized upper critical field from measurements
of the equilibrium isothermal magnetization, we analyze experimental data
obtained on polycrystalline and ceramic samples. We show that the scaling
procedure works quite well in all cases that we have considered. This provides
a very strong evidence that the temperature dependencies of the normalized
upper critical field are independent of the orientation of an applied magnetic
field with respect to the crystallographic axes of these materials.
