Columbia subject headings:
Premarital sex--Pennsylvania.
Sexual abstinence--Study and teaching (Secondary)--Pennsylvania.
Teenage pregnancy--Pennsylvania.
Harvard subject headings:
Premarital sex--Pennsylvania.
Sexual abstinence--Study and teaching (Secondary)--Pennsylvania.
Teenage pregnancy--Pennsylvania.
Princeton subject headings:
Premarital sex--Pennsylvania.
Sexual abstinence--Study and teaching (Secondary)--Pennsylvania.
Teenage pregnancy--Pennsylvania.