“…Numerous reviews and several books have been written on IGC. − Some of them were published 20–40 years ago. − Though being brilliant or simply useful, today they are rather outdated. In the 21st century researchers returned many times to the subjects of IGC. − A special book was published dealing with general questions of IGC. It should be noted that most of those reviews focused on such subjects as polymer surface studies and polymer blends, ,,, determination of T g and other properties of polymers, , investigation of surfactants, pharmaceuticals, and fibers. , Meanwhile, some important issues did not receive proper attention in the existing literature, for example, thermodynamics of glassy polymers, IGC as a probe method for investigation of free volume in polymers, and some others.…”