Gerhard, Ortwin Optical and Interpretative Astronomy, MPI for Extraterrestrial Physics, Max Planck Society;
Gerhard, O., Hatzidimitriou, D., Whitelock, P. A., Lada, C., Sarajedini, A., Wyse, R. F., et al. (2009). Division VII - The galactic system. In K. van der Hucht, & International Astronomical Union (Eds.), Reports on Astronomy (pp. 273-274). Cambridge, UK: Cambridge University Press.