  Large amount of observational spectroscopic data are recently available from
different observational projects, like Sloan Digital Sky Survey. It's become
more urgent to identify white dwarfs stars based on data itself i.e. without
modelling white dwarf atmospheres. In particular, existing methods of white
dwarfs identification presented in Kleinman et al. (2004) and in Eisenstein et
al. (2006) did not allow to find all the white dwarfs in examined data. We
intend to test various criteria of searching for white dwarf candidates, based
on photometric and spectral features.
