Four Laws That Drive The Universe By Peter Atkins -.pdf- Here

The Third Law, formulated by Walther Nernst, states that as the temperature of a system approaches absolute zero (the theoretical minimum temperature), the entropy of the system approaches a minimum value. This law provides a fundamental limit on the efficiency of energy conversion and explains the behavior of materials at very low temperatures. The Third Law also implies that it is impossible to reach absolute zero by any finite number of processes.