Keywords: System boundary pl.svg Illustration of concept of thermodynamical system System-boundary svg 2011-06-08 12 56 UTC System-boundary svg Polish version System boundary pl svg derivative work Joanna Kośmider <span class signature-talk >talk</span> Joanna Kośmider Polish version Joanna Kośmider System-boundary svg </nowiki> Uploaded with derivativeFX Systems |