Columbia subject headings:
Akselʹrod, P. B. (Pavel Borisovich), 1850-1928--Correspondence.
Revolutionaries--Soviet Union--Correspondence.
Socialism--Soviet Union--History--Sources.
Harvard subject headings:
Akselʹrod, P. B. (Pavel Borisovich), 1850-1928--Correspondence.
Revolutionaries--Soviet Union--Correspondence
Socialism--Soviet Union--History--Sources.
Princeton subject headings:
Akselʹrod, P. B. (Pavel Borisovich), 1850-1928.
Revolutionaries--Russia--Correspondence.