Cumper,George E. (1991). The evaluation of national systems. Oxford University Press.
Lua i Stíl Chicago (17ú heag.)Cumper,George E. The Evaluation of National Systems. New york: Oxford University Press, 1991.
Lua MLA (8ú heag.)Cumper,George E. The Evaluation of National Systems. Oxford University Press, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.