Internal friction - wide range

• Internal friction universality - RevModPhys

• 2006 Universal behavior of internal friction in glasses below Tg : anharmonicity vs relaxation

diffs between strong and fragile glasses - the relative role of defects?

1999 Theory of Sound Attenuation in Glasses: The Role of Thermal Vibrations

• 2005 Anharmonic versus relaxational sound damping in glasses. II. Vitreous silica
  René Vacher, Eric Courtens, and Marie Foret

• Internal friction plot - 1986 Low temperature properties of glasses-unsolved problems - A K RAYCHAUDHURI

crystals vs glasses?