Cita APA

(1991). Report of the twenty first session London, 18-22 february, 1991. [s.l.]: World Health Organization.

Citación estilo Chicago

Report of the Twenty First Session London, 18-22 February, 1991. [s.l.]: World Health Organization, 1991.

Cita MLA

Report of the Twenty First Session London, 18-22 February, 1991. [s.l.]: World Health Organization, 1991.

Precaución: Estas citas no son 100% exactas.