Third components with elliptical orbits in the eclipsing binaries: BD and, SV Cam, V0836 Cyg & XZ CMi

This is our regular research in the field of cyclic O-C changes and third components. In this article the results of four new stars investigation is described. These stars are: BD And, SV Cam, V0836 Cyg and XZ CMi. All of them have cyclic O-C curve with linear (BD And, SV Cam and XZ CMi) or parabolic trend (V0836 Cyg). We computed the mass transfer rate, minima possible mass of the third component and their errors for each of the researched stars.