  We present the new results of our long-term observational project to detect
the small variations in the orbital periods of low-mass and short-period
eclipsing binaries. About 120 new precise mid-eclipse times were obtained for
three relatively well-known dwarf eclipsing binaries: SDSS J143547.87+373338.5
(P = 0.126 d), NSVS 07826147 (0.162 d), and NSVS 14256825 (0.110 d).
Observed-minus-calculated (O-C) diagrams of these systems were analyzed using
all accurate timings, and, where possible, new parameters of the light-time
effect were calculated. For the first time, we derive (or improve upon previous
findings with regard to) the short orbital periods of 13 and 10 years of
possible third bodies for SDSS J143547.87+373338.5 and NSVS 07826147,
respectively. In these binaries, our data show that period variations can be
modeled simply on the basis of a single circumbinary object. For the first two
objects, we calculated the minimum mass of the third components to be 17 MJ,
and 1.4 MJ respectively, which corresponds to the mass of a brown dwarf or a
giant planet. For NSVS 14256825, the cyclical period changes caused by a single
additional body cannot be confirmed by our recent eclipse time measurements.
More complex behavior connected with two orbiting bodies, or yet unknown
effects, should be taken into account.
