Alan Guttmacher Institute. (1981). Teenage pregnancy: The problem that hasn?t gone away. Alan Guttmacher Institute.
芝加哥风格引文Alan Guttmacher Institute. Teenage Pregnancy: The Problem That Hasn?t Gone Away. New York: Alan Guttmacher Institute, 1981.
MLA引文Alan Guttmacher Institute. Teenage Pregnancy: The Problem That Hasn?t Gone Away. Alan Guttmacher Institute, 1981.
警告：这些引文格式不一定是100％准确.