Columbia subject headings:
Hart, H. L. A. (Herbert Lionel Adolphus), 1907-1992--Congresses.
Law--Philosophy--Congresses.
Harvard subject headings:
Hart, H. L. A. (Herbert Lionel Adolphus), 1907-1992--Congresses.
Law--Philosophy--Congresses
Princeton subject headings:
Hart, H. L. A. (Herbert Lionel Adolphus), 1907-1992--Congresses.
Law (Philosophical concept)--Congresses.