Beginning in 1926, Mandelstam and Landsberg initiated experimental studies on the vibrational scattering of light in crystals at the Moscow State University. Their intention was to prove the theoretical prediction made by Mandelstam in 1918 regarding the fine structure splitting in Rayleigh scattering due to light scattering on thermal acoustic waves. As a result of this research, Landsberg and Mandelstam discovered the effect of the inelastic combinational scattering of light on 21 February 1928 ("combinational" – from the combination of frequencies of photons and molecular vibrations). They presented this fundamental discovery for the first time at a colloquium on 27 April 1928. They published brief reports about this discovery (experimental results with theoretical explanation) in Russian and in German and then published a comprehensive paper in Zeitschrift für Physik.