Columbia subject headings:
Nelson, Leonard, 1882-1927--Congresses.
Philosophy--Congresses--History.
Harvard subject headings:
Analysis (Philosophy)--Congresses.
Nelson, Leonard, 1882-1927--Congresses.
Philosophy--History--Congresses.
Princeton subject headings:
Nelson, Leonard, 1882-1927--Congresses.
Philosophy--Congresses--History.