There are some Larry Niven and a Bear/Stirling stories available via
Webscription
INTRODUCTION
Larry Niven
THE WARRIORS
Larry Niven
MADNESS HAS ITS PLACE
Larry Niven
THE MAN WHO WOULD BE KZIN
Greg Bear and S.M. Stirling
These can essentially been read online or downloaded as html. If you like those stories (like I did), buy "The Best of all Possible Wars"