1592952530000 1312632483000 term-1982 1616540942884 1312632486000 1615829356273 adlib fitz-online adlib-term-1982 c7940e7c-db40-3ec9-998f-a1927611968f 2 1 stratification, social stratification, social term reference term-1983 adlib-term-1983 d08e78b5-047c-3830-ae0d-941e94005df1 social stratification