Comments and suggestions are welcome.
email: jolinton@btinternet.com
Rotation data for the Milky Way Galaxy is obtained from various sources
Rotation curve data for M31 is obtained from Seigar et al. (2007) Mon. Not. R. Astron. Soc. 000, 1-14
Rotation curve data for NGC3198 is obtained from Begeman (1989) Astron, Astrophys. 223, 47-60