Welcometo Mobileread!
There are many people (like myself) who don't own Kindles, but rather a myriad of other reading devices. For them it might be better to provide links for ePub versions of your books.
I found your book listings on Smashwords and see that they are available in various formats (including ePub) over there. So for those that might find it useful here's the links to Smashwords:
Right Ascension
Declination