Labor (2) Industries (2) Estudio (2) Industria (2) Trabajo (2) probabilité (2) industrie (2) Programs (1) Certification (1) Wages (1) Trials (1) Social security (1) Social sciences (1) Research (1) Public welfare (1) Policy sciences (1) Military service, Voluntary (1) Matter (1) Marketing (1) Manufacturing processes (1) Life (1) Human behavior (1) Health (1) Expenditures, Public (1) Environmental protection (1) Education (1) Character (1) Calculus (1) Business enterprises (1) Aircraft industry (1)