sack, k., & linsel, h. (1965). contents and measuring of labour productivity in socialist industry. the institute of national planning.
Lua i Stíl Chicago (17ú heag.)sack, kurt, agus hermann linsel. Contents and Measuring of Labour Productivity in Socialist Industry. cairo: the institute of national planning, 1965.
Lua MLA (9ú heag.)sack, kurt, agus hermann linsel. Contents and Measuring of Labour Productivity in Socialist Industry. the institute of national planning, 1965.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.