(1991). Essential Elements Of Obstetric Care Al First Referral Level. WHO.
芝加哥风格引文Essential Elements Of Obstetric Care Al First Referral Level. Ginebra: WHO, 1991.
MLA引文Essential Elements Of Obstetric Care Al First Referral Level. WHO, 1991.
警告：这些引文格式不一定是100％准确.