Cita APA (7a ed.)

Singer, H. W. (1968). Fifty years on: The United Nations and Economic and social development. [s.n].

Cita Chicago Style (17a ed.)

Singer, Hans W. Fifty Years on: The United Nations and Economic and Social Development. IDS: [s.n], 1968.

Cita MLA (9a ed.)

Singer, Hans W. Fifty Years on: The United Nations and Economic and Social Development. [s.n], 1968.