find it here
http://www.asimovs.com/2013_02/exc_story2.shtml
There are two more Nebula-nominated novellas. One I can't access, and one I dislike a lot. The Weight of the Sunrise is an alternate history of an Inca Empire that didn't fall, meeting an America that's British. I found it clunky, awkward, and unpleasant.
It lacked every gracenote writing can offer, and troweled on the info without any noticeable attempts to disguise the dump.