  We discuss the time-series behavior of 8 extragalactic 3FGL sources away from
the Galactic plane (i.e., $\mid b\mid \geq 10^{\circ}$) whose uncertainty
ellipse contains a single X-ray and one radio source. The analysis was done
using the standard Fermi \textit{ScienceTools}, package of version v10r0p5. The
results show that sources in the study sample display a slight indication of
flux variability in $\gamma$-ray on monthly timescale. Furthermore, based on
the object location on the variability index versus spectral index diagram, the
positions of 4 objects in the sample were found to fall in the region of the
already known BL Lac positions.
