Meshcheryakov, A. V., Revnivtsev, M. G., Pavlinsky, M. N., Khamitov, I., & Bikmaev, I. F. (2010). Measurement of the orbital period of the X-ray burster GS 1826-238 based on observations of its optical brightness variations. Astronomy Letters-A Journal of Astronomy and Space Astrophysics, 36(10), 738-751. doi:10.1134/S106377371010004X.