Worcester, D. A. (1969). The optimal employment level, the negative income tax and an alternative suggestion. Institute of Economic Development and Research, University of the Philippines.
Lua i Stíl Chicago (17ú heag.)Worcester, Dean Amory. The Optimal Employment Level, the Negative Income Tax and an Alternative Suggestion. [Quezon City]: Institute of Economic Development and Research, University of the Philippines, 1969.
Lua MLA (9ú heag.)Worcester, Dean Amory. The Optimal Employment Level, the Negative Income Tax and an Alternative Suggestion. Institute of Economic Development and Research, University of the Philippines, 1969.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.