This is a fairly high res picture of the clay stoves, mostly for burning charcoal at the Asian Institute of Technology.
What is remarkable is now poor the thermal efficiency is for all of them. It should be 40% for a decent charcoal stove so I am wondering how they measured them.
It is probably worth putting them on the website as group though I don't know how you would categorize the pic.
Asian Clay Stoves perhaps.
Crispin in JHB