Biblio

K. Grabowski, Carlin, J.  L., Newberg, H.  J., Beers, T.  C., Chen, L., Deng, L. - C., Grillmair, C.  J., Guhathakurta, P., Hou, J. - L., Hou, Y. - H., Lépine, S., Liu, C., Liu, X. - W., Luo, A. - L., Smith, M.  C., Yanny, B., Zhang, H. - T., Zhang, Y., and Zheng, Z., “Fixing the reference frame for PPMXL proper motions using extragalactic sources”, Research in Astronomy and Astrophysics, vol. 15, p. 849, 2015.