In the period 1911 to 1930, as physical understanding of the behaviour of electrons in metals increased, various different theoretical expressions (based on different physical assumptions) were put forwards for AG, by Richardson, Saul Dushman, Ralph H. Fowler, Arnold Sommerfeld and Lothar Wolfgang Nordheim.
European emission standards | Positron emission tomography | spontaneous emission | positron emission tomography | Emission Impossible | Stimulated emission | Spontaneous emission | Low-ionization nuclear emission-line region | Bharat Stage emission standards | Thermal Emission Spectrometer (TES) | Thermal Emission Spectrometer | stimulated emission | Spurious emission | Soft X-ray emission spectroscopy | Self-amplified stimulated emission | nocturnal emission | Emission spectrum | Advanced Spaceborne Thermal Emission and Reflection Radiometer |