Columbia subject headings:
Christian sociology.
Habermas, Jürgen.
Luhmann, Niklas, 1927-1998.
Harvard subject headings:
Christian sociology.
Habermas, Jürgen
Luhmann, Niklas, 1927-1998
Princeton subject headings:
Christian sociology.
Habermas, Jürgen.
Luhmann, Niklas, 1927-1998.