00544naa#a2200169#i#450# EN\\bibl\536 20250123062855.4 1999-9836 20131023b2013####ek#y0engy0150####ca RUS RU Assessment of the number of middle class among employees based on criteria of labour market position and material security Journal article Moscow All-Russian center of living standards 2013 3 с. Journal article local Odintsova Elena zh-szf.ru