Looking for a book called Dragonstar


Years ago in Analog I read a story called Dragonstar about a huge cylinder in orbit around our sun and the reptile-like beings humans found living in it when they went to investigate. Recently I've been trying to find a place to buy the book. What I've been led to believe is that it's a trilogy and if it is I've only been able to find the third book in the series. Does anyone know if the author of what I'm remembering is David F. Bischoff? Does anyone know where I can get copies of all the books in the series if so, or what I really am remembering if not?

Thank you for any help!