  The quantum de Haas van Alphen (dHvA) and Shubnikov de Haas (SdH)
oscillations measured in graphite were decomposed by pass-band filtering onto
contributions from three different groups of carriers. We develop the
two-dimensional phase analysis method which allows to identify these carriers
as (i) minority holes having two-dimensional (2D) parabolic massive spectrum,
(ii) majority electrons, also massive but with intermediate 2D-3D spectrum, and
(iii) majority holes with 2D Dirac-like spectrum which seems to be responsible
for the unusual strongly-correlated electronic phenomena in graphite.
