On The Edge Of Disaster;
Winter II; and
Another story set on the same world is It's Different Here.
The Rensa stories are set in the same universe but on a different planet.
The other stories in the same universe are:
Fire Sign I ;
Return Visit – this one explains quite a bit about the background, although it is very short.; and
Background pieces for Rensa which apply to the setting generally are:
Rensa's Universe Background Information Entry; and
Rensa's Universe: Background 2.