Não informado. Progress in Standardization. World Health Organization.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Progress in Standardization. Geneva, Suíça: World Health Organization.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Progress in Standardization. World Health Organization.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.