| http://digfir-published.macmillanusa.com/astro_interactive_exercise/ie_main-sequence_stars_of_different_masses.html |
Chapter
1. Main-Sequence Stars of Different Masses
| 5139df91b11c0f114e000000 |
| http://digfir-published.macmillanusa.com/astro_interactive_exercise/ie_main-sequence_stars_of_different_masses_dlap.xml | DLAP questions | 5139df91b11c0f114e000000 |