Columbia subject headings:
Catholic Church--Relations--Orthodox Eastern Church.
Christian union--Soviet Union.
Orthodox Eastern Church--Relations--Catholic Church.
Solovyov, Vladimir Sergeyevich, 1853-1900.
Harvard subject headings:
Catholic Church--Relations--Orthodox Eastern Church.
Christian union.
Orthodox Eastern Church--Relations--Catholic Church.
Solovyov, Vladimir Sergeyevich, 1853-1900
Princeton subject headings:
Catholic Church--Relations--Orthodox Eastern Church.
Christian union--Soviet Union.
Orthodox Eastern Church--Relations--Catholic Church.
Solovyov, Vladimir Sergeyevich, 1853-1900.