Unable to locate package ros--strands-perception-people

[Algabri]

sudo apt-get install ros-$DISTRO-strands-perception-people
also the same issue with
sudo apt-get install ros-$DISTRO-strands-qsr-lib

Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package ros--strands-perception-people

I followed all your steps, started from here http://wiki.ros.org/indigo/Installation/Ubuntu#Installation to last step sudo apt-get update

my system
indigo
please help me

thank you in advance