Columbia subject headings:
Esperantists--Biography.
Esperanto.
Jews--Europe.
Zamenhof, L. L. (Ludwik Lazar), 1859-1917--Religion.
Harvard subject headings:
Esperantists--Poland--Biography.
Esperanto language.
Esperanto.
Jews--Europe.
Zamenhof, L. L. (Ludwik Lazar), 1859-1917--Religion.
Princeton subject headings:
Esperantists--Biography.
Esperanto.
Jews--Europe.
Zamenhof, L. L. (Ludwik Lazar), 1859-1917--Religion.