  White dwarf symbiotic binaries are detected in X-rays with luminosities in
the range of 10$^{30}$ to 10$^{34}$ lumcgs. Their X-ray emission arises either
from the accretion disk boundary layer, from a region where the winds from both
components collide or from nuclear burning on the white dwarf surface. In our
continuous effort to identify X-ray emitting symbiotic stars, we studied four
systems using observations from the Neil Gehrels Swift Observatory and
XMM-Newton satellites in X-rays and from TESS in the optical. The X-ray spectra
were fit with absorbed optically thin thermal plasma models, either single- or
multitemperature with kT $<$ 8 keV for all targets. Based on the
characteristics of their X-ray spectra, we classified BD Cam as possible
$\beta$-type, V1261 Ori and CD -27 8661 as $\delta$-type, and confirmed NQ Gem
as $\beta$/$\delta$-type. The $\delta$-type X-ray emission most likely arise in
the boundary layer of the accretion disk, while in the case of BD Cam, its
mostly-soft emission originates from shocks, possibly between the red giant and
WD/disk winds. In general, we have found that the observed X-ray emission is
powered by accretion at a low accretion rate of about 10$^{-11}$ M$_{\odot}$
yr$^{-1}$. The low ratio of X-ray to optical luminosities, however indicates
that the accretion-disk boundary layer is mostly optically thick and tends to
emit in the far or extreme UV. The detection of flickering in optical data
provides evidence of the existence of an accretion disk.
