00302nam a2200109Ia 450000500170000000800410001708200150005810000240007324500400009726000470013730000080018420260225050943.0260224s9999||||xx |||||||||||||| ||und||  a621.56 SEV  aWilliam H. Severns  0aAir conditioning and refrigeration   aIslamabad: National Book Foundation c1958  a563