Columbia subject headings:
Harvard subject headings:
Apologetics--Early works to 1800
Apologetics--Early works to 1800.
Apologetics--History--17th century
Catholic Church--Apologetic works.
Catholic Church--Doctrines--Catholic authors.
Catholic Church--Doctrines.
Princeton subject headings:
Apologetics--Early works to 1800.
Apologetics--History--17th century.
Catholic Church--Doctrines--Catholic authors.