Cita APA (7a ed.)

Helmer, O. (1967). Systematic use of expert opinions. Rand Corporation.

Cita Chicago Style (17a ed.)

Helmer, Olaf. Systematic Use of Expert Opinions. Santa Monica, California: Rand Corporation, 1967.

Cita MLA (9a ed.)

Helmer, Olaf. Systematic Use of Expert Opinions. Rand Corporation, 1967.