https://doi.org/10.1351/goldbook.B00755
@R05381@ may be conveniently divided into bulk @R05381@, in which effects due to the surface of the system can be neglected, and surface rheology, in which such effects are predominant. It should be noted that in surface rheology the neglect of bulk behaviour is permissible only in exceptional circumstances, such as for very thin films surrounded by a gas.