1. Binney, J., Tremaine, S. (1987): Galactic Dynamics (Princeton University Press, Princeton)
2. Burton, W.B. (1988): “The Structure of Our Galaxy Derived from Observations of Neutral Hydrogen”, in Galactic and Extra-Galactic Radio Astronomy, 2nd ed., Eds. G.L. Verschuur, K.L Kellermann (Springer, New York, Heidelberg, Berlin) p. 295
3. Dickey, J.M., Lockman, F.J. (1990): Ann. Rev. Astron. Astrophys.28, 215
4. Genzel, R. (1991): Physics and Chemistry of Molecular Clouds in Galactic Interstellar Medium, Ed. W.B. Burton et al. (Springer, Berlin)
5. Hartmann, D., Burton, W.B. (1997): Atlas of Galactic Neutral Hydrogen, (Cambridge University Press, Cambridge)