600 Soviet POWs were gassed with Zyklon B at Auschwitz camp I; this was the first experiment with the gas at Auschwitz.
Editors. "First mass killing by gas at Auschwitz". The Literary Encyclopedia. First published 01 February 2010; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=3096, accessed 27 April 2015.]