Apsidal motion and light-time effect in eclipsing binaries HS Herculis and U OphiuchiM. Wolf, P. Harmanec, R. Diethelm, K. Hornoch and P. EenensA&A, 383 2 (2002) 533-539DOI: https://doi.org/10.1051/0004-6361:20011729
